Having a transmother is cool sometimes (like it's cool because she gets me and has no problem with my transsexuality) but it's also... weird sometimes, and she can be annoying about it. It's weird because at times I can't see my "dad" at all, but others, I can see nothing BUT my "dad". Also, sometimes she thinks having changed her sex males her some kind of special (we have philosophical discussions a lot, and she posed to me the theory that she is a god--one of her "proofs" is "I changed my sex, and that's something gods do". I know she's not really serious, but it pisses me off, lol).
In general, though, she's a better mom than my bio-mother.