I'd say more 3.5 than 3.0.
I really enjoyed my 80-minute French Lavender Soothing Massage; however, the women's spa is really small and there isn't much to do in terms of finding a quiet space. I couldn't find a place to lounge and read. The hot tub capacity is 6 people, so you can imagine the size for yourself. Despite its size, you'll find all you need in terms of amenities. Keep in mind that Vdara is a non-casino condotel so the spa is nothing like Qua at Caesar's or the Bellagio Spa or Aria's. I went here out of convenience because I was staying at the hotel. I likely will not be back.
HI: good treatment.
LO: small space.