[W126 Coupe] R-134, should I worry?

[Shayegan, Richard]

As part of the repair process, the body shop (looks good by the way...the guy who does their bitch work is apparently messy, left stuff everywhere, but their paint guy and the guy who does the body work is very good) had their A/C guy retrofit my A/C to R-134, rather than just replace the broken parts. I kinda wish they asked me first, though I suppose I don't really care since it didn't work at all before. The guy who did it wasn't around, but I'm told their retrofits typically involve replacing valves, hoses, tubes, oil, and freon. Does that sound like a retrofit that will last? I know for now it's blowing ice cold, but I've heard a lot about retrofits gone wrong. If it's good now (blows as cold as any new car, and colder than I remember my 380 blowing about 7 years ago when the A/C worked), does that mean it's a good retrofit?
Thanks,
Richard