Can't say I've been able to give it particularly heavy use, but I bought a 312a last year, and it's been wonderful for solo and duo gigs and as a monitor for my full band. I think it sounds as good (and to my ears a little better) than the QSC K12, and it was half the price. The only drawback to the speaker from what I can tell is the limited input section (just one XLR in, one XLR out, a selector for mic/line level, and a volume knob). It's also not quite as pretty as the QSCs, but it's a great little speaker, and I think very hard to beat in its present USA price-range. I paid $450 for mine, but they're going for a little under $400 right now on ebay. $760 for a pair.
I played in an acoustic duo for a while with a guy who worked at a mail order place in town and had access to everything. The RCF cabs he had were impressive but expensive even at his cost. Amazing gear though with really small and light powered cabs and they sounded great. The QSC powered stuff was also very nice and a much better value. They sounded just about as good if you took the time to really tweak it for the room.
I can't comment on that. The gear I used worked very well and no need for servicing. The company is located in Italy so I could see where that could present problems should there ever be a breakdown. However, the stuff really seems to be dialed in and it works very well.
My band is using RCF 312-A for powered mains and the "matching" subs. We use them for full band and couldn't be happier with the sound quality and durability. The cabs are lightweight. We use this system in clubs for up to 200 people and it's plenty sufficient. The crossover settings in the sub give you a couple of options but are basically set it and forget it. A/B'ed them in the store with the similiar offerings from QSC and for my money there wasn't much of a choice.
I've had a pair of RCF ART500A since they first came out @ 10-years ago and they are awesome. They've been stored (in covers) in my trailer that whole time and I've never had a problem with them. I can't comment on service as I've never required it. I've had 4-Yorkville NX-520p for nearly the same time, stored the same way and have had no problems with them either.
I just bought a pair of RCF ART312a's for mains with my trio in small to medium venues and so far I'm very happy. I did a load of research first, looked at Mackie SRM450's but didn't go ahead because of reliability and servicing problems. The RCF's are seemingly more reliable and better sounding (they built the early Mackies) and ideal for what I want. I'm in the UK, got a three year warranty and I've been assured that servicing is not a problem....we'll see. I also listened to the K12's; they sounded good to me and of course are 1kw instead of 350watts, but here they are also half as much again price-wise.