The only experience I have with Mares gear is their regs, I've got a few of their older regs (Voltrex and Ruby) among my spare gear 'reserves', and I was open water certified on base model Mares regs, so that's what I bought as a new diver. I've been pleased with Mares regs, reliable, no problems. My main 2 'issues' with Mares regs are 1) distant supply chain (Italy) so sometimes parts can be harder to get or on backorder for a while...2) non-diver-adjustable 2nd-stages, overall, I prefer to have an adjustment knob on my 2nd stages (more diver control in the field) so my 'main' regs these days are Atomics/Apeks/Aqualung.
...based on what I've seen other divers with Mares BCD's experience, I'd avoid Mares BCD's though......I've witnessed some pretty horrible weight system designs/flaws in other diver's Mares BCD's...flimsy/unreliable weight pockets/inserts. Unfortunately, Mares isn't the only gear manufacturer with crappy weight systems...on my trip to Belize/Sun Dancer I witnessed my dive buddy lose a weight pocket on a brand new Aqualung Seaquest (I think it was a Seaquest). What's even funnier though, the boat crew had spare weight pockets to fit my buddies BCD which they're recovered off the ocean floor from all the other prior Aqualung Seaquest divers who'd previously lost weight pockets on earlier trips...a sad commentary on the Aqualung design!
I'm using a Halcyon weight system on my custom built harness/wing.....Halcyon stuff isn't the cheapest, but sometimes the tech boys DO know what they're doing (and how to properly design a weight system) whereas the recreational gear manufacturers often don't have a clue!