My carb came with the engine core I purchased about 20 years ago. My IA at the time pronounced it good, and with a few seal (and one float) replacement, that carb performed well for me for 19 years. But, I'd started noticing play in the throttle shaft, the bowl to body seal was wiggling again, and I thought it was time. So I swapped it out for a rebuilt unit.
The only complaint I have is that the casting for my old carb didn't match the casting for the new one, so the bolt-on fit I expected didn't exactly work out. Instead, I had to modify the airbox mounting plate to get the new carb to seat.
If I hadn't been in a hurry, I'd have sent the carb to Aircraft Accessories of OK (Phone - 918-835-9924). They were Rhonda at Barrett's Precision Engines recommendation. They were nice on the phone and the price of their IRAN and/or overhaul would have been less than or equal to the replacement carb's price from Aircraft Spruce. They were looking at a 7-10 day turnaround, wheras I could get one same day from Spruce by driving down there.
So, if I was willing to wait a week or 10 days, I'd go with Aircraft Accessories. If I was in a hurry, I'd get a rebuilt unit from Spruce. The one I got looked brand new.