Eh, first, I don't believe in that whole "gender =/= sex" stuff, that's GC/TRA territory. Tbh, I see them as the same thing. The only difference is transsexuals are the ones who would go through medical "transition," (especially getting bottom surgery) and the likes. Transgenders do or don't put the effort in.

If I'm not mistaken, the whole transsexuals vs transgenders thing also began because some in the past didn't like that transsexuals had "sexual" in it. Alongside, it was also a term used in porn. There were even some actors in the past would've gone under transsexual (esp if they had bottom surgery) but still choose to call themselves "transgender."