"In fact, SAYC 2/1 sequences work almost as well as 2/1 game force sequences."
I agree that you don't have to play 2/1 to have decent 2/1 bidding.
With one pd, I play standardish (F1) 2/1 responses. Responder promises a rebid except after 1M-2x-2M, which is a minimum which wouldn't accept an invitation to 3NT, and is frequently 5 cards, and after 1S-2H-3H, which is invitational. All other rebids by opener are forcing, and all except 1M-2x-2y, where y is lower ranking than M, are GF. BTW, we play 10-13 NT.
I play "club 2/1" with a couple of pds. I don't mind it. The 2/1 sequences are sometimes better than the standardish system, but overall, the differences aren't much. I don't like the forcing NT much, so 2/1 loses there. Overall, I think a decent "2/1 F1" system bids games and partscores a little better than 2/1, and slams a little worse.
Matchpoints, anyone
Peter