I've shot the Monster and the Reezen 6.5 half a dozen times in the last 2 weeks. I'm a Mathews fan anyway, so I liked both of them for what they are.
The draw cycle on the Monster is smooth until the big "hump" at the end, but the valley is deep and the back wall is solid--creeping should not be a problem. It's shooting through the chronograph at 290 fps with a 450 grain arrow at 64+/- pounds and 29" draw. It's a speed bow, but the hand shock is tolerable and the noise isn't what you'd expect. The bow I shot had the "Dead End String Stop" on and it makes a difference.
The Reezen is a lot smoother--and it is meant to be. I shot it side by side with a Drenalin I just bought on ebay, and the draw cycles are very similar. I didn't chronograph it, but I will next time I get a chance. It shoots very nice--with the "Dead End" installed there is almost NO discernible hand shock and it is noticeably faster than my Outback with 450 grain arrows. The Outback shoots 262 fps at 67 pounds 29" and I would guess the Reezen is 280ish.
Bottom line is that if you like speed bows you'd probably like the Monster. If you like smoother, milder mannered bows, the Reezen may be more your style.