Sassy Nail Bar is by far my favorite nail salon in Charlotte (and I've been to over 15 over the past 6 years).
Reservations: Yes, they get crazy busy - they're great and people know it. That being said, they take reservations! And not one of those reservations where you still wait 75% of the time you would have otherwise. I made a reservation on a busy Saturday afternoon for 5 pedicures and they had us on the books and seated within 5 minutes (there was a 45 minute wait otherwise).
Drinks: Like all Charlotte salons, they serve wine and beer complimentary with your service. Unlike other salons, they also have a selection of other delicious drinks like white peach margaritas (yum!) which one ups the other salons.
Quality: I have found that my polish lasts longer with Sassy. My gel nail polish never chips or peels before I replace it. I also find that they don't rush so you feel like you get your money's worth.
Husband Friendly: I will sometimes bring my husband along if his feet need a pedicure. I'll get him the longest pedicure which includes paraffin wax and such. I'll get a normal mani/pedi and they'll often get two women to do both of mine at the same time. That way, my mani/pedi is done at the same time as his pedicure so he's not just waiting around. They don't offer this at most salons and that's why my husband likes Sassy (and he says they don't rush his pedicure).