Hmm... I'm not sure you can go wrong with HM2 or PT4 to be honest. I'd do the free trial of each and see what your learning curve is for both of them.

Based on the guys I talk to, they tend to prefer HM2 for in game play, but the PT4 hand replayer is way better. 

As far as how hard it is to understand? I'd start with the basic pre flop stats, especially for tournaments. Once you get a feel for reading it on the fly and understanding you need a decent sample size of data for reliable decision making it's not so bad. 

The last thing I will say about MTT HUD usage - you'll have no clue at what stages of tournaments this data was collected nor what stack sizes the people had when you collected data and so you must consider this when making decisions. It's not as straightforward as using it for cash games. 

Thanks man I appreciate the feedback ! I am going to take your advice and check out both.

Hi Lowrider. If you want it to MTTs, I recommend you PT4. I bought it over HM2 because he used much less resources from the computer, but what a nice suprised I had when I discovered the autonotes software that PT4 has. To play MTTs it's an amazing tool that will help you a lot once you've played a big amount of MTTs. Hope this helps!

PT4. 

And I filter my stats for specific stack sizes to know how active they are deeper stacked and how they play a short stack.

Autonotes is awesome, beyond that, HUDs aren't really all that necessary for MTTs imo. I'd keep it simple, 3 Bet %, Fold to 3 Bet %, C Bet %, Fold to C Bet %, Steal % and of course VPIP, # of hands on the player, number of big blinds, and the notes. Everything else you can just use the drop downs, but honestly unless your playing with a bunch of sick regs you have tons of hands on the numbers don't mean much.
If you rely too much on stats in MTTs it can really hurt your game. Just because a guy has a 2% 3 Bet over 500 hands doesn't mean that he doesn't manically 3 Bet near the bubble or at the final table. The change of dynamics throughout the tournament can really manipulate what the numbers are telling you. With that said, be sure to make your own decision first and use the stats to back it up if the situation is right. Like the above poster said, filtering by stack size is a good route, but even that can be way off given the situation that you're in. Use it as a guide, not an answer.

Oh, and PT4 for sure.

Hi, I am lead designer at ProPokerHUDs. You might be interested to know we have just released a professionally designed MTT HUD for PT4, with many features never seen before in any HUD.

http://forumserver.twoplustwo.com/167/commercial-software/poker-huds-reinvented-propokerhuds-mtt-hud-free-15-day-trial-1392994/

If you guys are interested, we have a free 15-day free trial available from the link the thread.

 (mods if this is classed as spamming, I apologise and remove).