I always used halflings, but NOT the Tolkien variety. They were usually either urban, gypsy-like, or pirates (both on rivers and seas) before WotC got the same idea. Because in my campaigns small, idyllic, bucolic villages don't exist.
I always use 22 pt buy, and I don't think it makes some classes less viable. MAD does not really occur in 4E unless you're trying to build characters who can do everything. For instance, there are Warlords who depend on STR and either CHA or INT, Warlocks depend on CHA or CON and INT, and so on...