The Aqualung Mikron is physically smaller and more lightweight than the Legend Supreme that I dive. It's not specifically made for women, but there is indeed a black/red version and a white/pink version. The pink ("women's") version comes with a smaller bite wing. I've had several women divers buy these and rave about them.
As far as quality and ease of finding local service go, both Aqualung and ScubaPro have strong worldwide presence, so that's what I personally own. I don't want to be stuck someplace needing service with Oceanics, because they just don't have the international presence I require. Atomics, are not easy to get service for either. I haven't ever dived with Mares regs, but the company has a similar global reach to Aqualung and ScubaPro. Personally, I've got my Legend Supremes that I dive normally, and my backup regs are a ScubaPro MK25/S600. (This is only for the recreational diving--I've got Apeks for tech.) Between the Aqualung and the ScubaPro, both breathe equally easy, but the ScubaPros are a little noisier.
