I could be wrong, but isn't a hud not really effective in MTT's as players have to change styles depending on the stage of the tourney.
Pam, granted I don't play very many big MTTs, but in my experience HUDs don't keep you from changing style, in fact they can help you if you use them properly. I'd argue they're at least 60% as effective in MTTs as in cash/SNGs, and much more if you're multi-tabling. Even single-tabling a slow structured, large field MTT, you'll often sit at the same table with most of the same players for an hour or more and certainly see enough
hands to leverage the villain stats that converge over a relatively small sample (VPIP, PFR, AF, cbet, fcbet, steal, etc). The more specific stats like 3/4/5bet that require larger samples will only be useful against the MTT regs that you run into a lot, but that doesn't diminish the importance of a HUD.
For instance, from HEM's HUD you can access a pop-up that shows stats broken down by stack size windows, which is particularly suited to tournaments. So you can get an idea of how villain adjusts as his stack dwindles or he chips up.
Obviously HUDs don't make decisions and aren't meant to take into account all the different aspects of MTT play. They're just meant to provide you stats so that YOU can make the adjustments needed based on your awareness of the factors like bubble proximity, stack sizes, antes, etc. Another for instance, if you're an M enthusiast, it can be configured to display color-coded M-zones that you can respond to at a glance.
From what I've heard recently (as opposed to the early days when I used it), PT3 offers better MTT support now with regards to filters and reports. HEM reportedly has a better HUD. HEM has its roots in cash games and its database was designed with cash in mind, which has made it harder for them to be as agile with adding MTT support. That's not to say HEM isn't useful for MTTs, but if I played primarily large field MTTs then I'd probably lean back toward PT3 (and I'd keep HEM for the other game types). As it is, since SnGs and cash are 90% of what I play, I personally think HEM is still the best and have never really looked back at PT3.