We had our son's TT clipped at three weeks, because I was in a lot of pain. It took a few more weeks for my pain to decrease, because he had to relearn how to nurse using his "new" tongue. Also, I think it just took a while for my nipples to heal due to the damage caused by his poor latch/suck before the procedure.
I was nervous and really drilled my ped for info, and she couldn't give me any reason not to get it done. Like the PPs said, there's a decent chance that a true TT can cause speech problems later on, and a frenectomy in an older child is much more complicated and will probably require general anethesia. My son's TT was obvious, the very tip of his tongue was connected to the floor of his mouth, making his tongue heart-shaped when he cried. Now, it looks totally normal, and you'd never know there used to be a frenulum there. The mouth heals so quickly.
IMO, it's definitely worth getting it done, and if it is causing you latch pain, the sooner the better. It hardly seemed to bother our baby at all - he cried when the doctor held his head, but the actual snip didn't seem to cause him any pain. He nursed immediately afterward and we were sent on our way.