McCormack REV B upgrades. Better than a new amp?


I have read the testimonials about the stellar performance of upgraded versions of McCormack amp,especially the "REV B" level. A "used good condition" McCormack DNA-1 bought for 750.00, with REV B. upgrades added later is approx 1600.00 with round trip shipping costs. Would it make more sense to find a another amp that is newer, though USED between $1200-1500?? Also, do the McCormack upgrades hold up over time??
sunnyjim
FWIW, I think Rev A, B refer to the DNA 0.5, 1, 2 series while Silver Gold Platinum refer to the newer DNA 125/250 series of amps that were built after CJ bought McCormack. Either way, Steve McC and Chris @ SMc Audio are a great resource. If I were still in solid state, I'd still have my SMc A+ amp.
I think in the used market you're better off waiting for a Rev A unit or better. Given the cost of these units on the used market vs. buying one (new or used) and upgrading it makes buying an already upgraded amp a great bargain. I'd skip Rev B and get either a Rev A or Platinum given the discount on the used market and the significant upgrade in performance. Best of luck.
Oh, forgot to answer your question about reliability. I'm the third owner of my 0.5 Rev. A and have had it for 14 years with fairly heavy use. The only thing I've had to do is replace a fuse, and as far as I can tell the amp sounds the same as it did the day I got it. Steve's also great about support if ever needed.