Err, I dunno how people have trouble with hammer slam. Looking at boulder roll, the stun time is 1.5 seconds at level 1. Rook's slam takes 1.5 seconds to cast at all levels. Thus, slam becomes easier and easier to line up as time goes on. When you then consider that Slam is capable of hitting multiple DG's and their minions, it becomes amazing.

There is such an item sadly it costs 250 Oh noes! Doom!

learn to play better maybe?

if u hate spit so much, theres this favor item u can get and its called "symbol of purity" if i remember correctly.
that will make max lvl spit only do TB's lvl 1 fireball dmg. May save you quite a lot of hassle.

Well right now i'm trying Rock, and I have to admit, this char is wonderfull !! I have no idea why can't you hit target with boulder roll + hammer slam. I have like 90% successfull hits (just where I wanted). As soon as you get boulder roll lvl 2, I really don't know how can u EVER miss the target.

To fight versus beast there is great tactic. Set up 4 towers in a line (if you like hammer slam build, 4 towers won't destroy this build anyway), and always stay behind those towers. If you see beast is trying to split you, just move back. When beast is right on towers, stun him with boulder roll and instantly move in his direction (you will probably not reach him, but your archers/tower of light/trebuchet should do the job - if not kill him, make him run to crystal, so you won that little battle). As soon as you master this technique, you will see even when beast reach and splits you, he will obviously lose MUCH more hp that you. Oh, and if the beast if smart enought, to not go into your towers, just push tower line forward step by step. Yeah, I know it takes a lot of mana, that's why i use 2 mana helmets in my rock build so i don't really have big mana problems when I fight like this. It's effective against any char, not only beast. Chars, that CAN make you some problems are Regulus (good Regulus is the pain in the ass), TB (ice build is the worst nightmare for rock) and Vampire/QoT/Oak/Sedna (ONLY FULL minions build, but you don't see those builds often). From all that chars build, you will see only well played Regulus often, so not many true counter-chars to deal with

Hammerslam is perfectly viable at all levels, you just need a little practice with it.  Things to practice:

• Cancelling the hammerslam before it goes off. Chases someone away, if they do NOT run, simply fail to cancel, and gasp, hit instead.
• Anticipating an opponents move. You know that TB is about to fireball you, so start slamming him when he goes into the animation, or start a little early, and if you are right, you get a good solid hit, if you are wrong, and he runs, just cancel.
• Helping a friend. Sometimes you can figure out where someone is going to be in 1.5 seconds, because they are either running away from, or running toward, one of your allies.
• Use the Keyboard! Boulder, click, hammer, click.  The stun on boulder is 1.5 seconds even at RANK 1.  The main cause of you not getting the slam in in time, is because you simply are taking too long to select hammer slam, and selecting the target.  If you combine mouse and keyboard, you can greatly decrease this time.  I have a friend who still uses just the mouse, and he rarely if ever can rook/roll at level 5.
  

The opponents should be under the effects of roll at level 5+, meaning your slam's a free hit. At lower levels, your passives are so sweet that if you wait for the opponent to blow their interrupt before you slam, either you get a free slam off, or they end up losing health way too fast to stay in the fight. Remember that you're a tank, you've got time to spare.

When people ask for Hammer Slam to be buffed, I think they forget that it deals 1700 damage at max level, more than a TB fireball or a sedna pounce. They forget, too, that UB's spit takes 10 seconds for its full effect to be unleashed, and is quite easily countered with priests/sedna/items when they ask that Spit be nerfed.

Venom Spit

= Same total damage as Hammer Slam at all levels
+ Short cast time (difficult to interrupt/avoid/miss)
+ Ranged
+ Shorter cooldown than Hammer Slam
- Most damage is dealt over time as debuff
- Higher mana cost than Hammer Slam
- No area effect damage (single target only)

Hammer Slam

= Same total damage as Venom Spit at all levels
- Very long cast time (easy to interrupt/avoid/miss)
- Short range
- Longer cooldown than Venom Spit
+ All damage is dealt immediately
+ Lower mana cost than Venom Spit
+ Area effect damage (both for low-damage radius and full damage)

Spit does get a static damage-over-time area effect at level 15 of course, but that's when Slam gets its slow debuff.

There're also other comparisons & contrasts between them that can't be quantified as well.  For example:
-Both are excellent tools for scaring people away.
-Spit is better used for harassment while Slam is a bread-and-butter nuke.
-Spit's much better in the early game before people get their health regen up, and Slam better later when you can stun people with Roll II and III (in fact at that point you'll be doing more damage than Spit with the combo and practically ensuring it will land, at cost of more mana).
-Spit's great for wearing down buildings without taking damage, and Slam is great against creeps.

This is true.  I find Roll II to mainly be better because there's virtually no chance of missing though whereas with Roll I you must be perfect.  Also, if you have the timing perfect for Roll I, you can do when still a couple steps away with Roll II.

I've seen Rooks kill 2 DGs at the same time with a hammerslam. You just need to figure out the correct timing and predict where you opponent is going. Also like many others have said it's really dumb to compare just skills, you have to look at the entire DG skill set and stats to see if something is balanced or not. I can't count the times a Rook saved my ass with a boulder roll or how many times we absolutely destroyed a guy with a boulder roll + pounce/snipe/whatever + hammer slam combo.

Finally a lot of DGs can counter spit using a shield or whatever. The damage from the hammer slam on the other hand is instant and it will kill minions easily so harder to counter (especially after getting stunned).

I find problems dealing with a rook with any melee type. Usually I play EB with all the health/armour/regen bonuses as well as skills for regen, bite and minions. Any non-noob rook cleans me up easy unless I am many levels above them.

I end up getting hit with boulder then hammer slammed, then they've been using speed boots/divine and just run me down. If they don't use that, they just spam towers. So a two on two on the tournament ladder, usually results in me and teammate losing. I've not found a demigod that is a suitable counter. I've used UB and while it can cause them some nasty damage, they either potion it off or port to base. Torch bearer doesn't do sufficient damage at lower levels and apart from fireball they other skills require getting to close, and been low hp, basically any hit with hammer a few levels in will leave you all but dead.

You realize that they will have to change its name from Spit to Throw Up!