I've played ultrasound methods (including very sound weak twos) at matchpoints, it seems to give you a nice low variance game of about 56%. Most interesting result was that I found that I didn't really need 2C as an artificial game force - I either played all one bids as forcing as per Fantoni-Nunes or put my GF hands through 1C as per Nightmare and others. Personally, I think that the frequency of Trent weak twos is too low (Terence Reese, Zia Mahmood and others happen to disagree). I used Fantoni-Nunes two bids for a while (these are just natural 10-13 unbalanced) but the responses are a bit tricky for me. My preferred methods now are to open 2C/D on 10-13 points 4+ cards with a 5+ card major and respond as per the Multi 2D. 2H/S similarly show a 4+ card major and a 5+card minor. Also, some Precision players I know use 2C/D as 10-14 unbalanced, no major better than xxxx. (They open 1D on any unbalanced hand with a decent four card major). What all of these methods have in common is that the opps overcall at their peril. I think that when you open at the two level, you should be trying to win a part score battle, not trick the opps out of game. The core should be hands from the 9-11 point range which will give you high frequency, a good success rate, and an accurate definition. What you add on to that is up to you.