When registering for Wireless@SG a few years ago, I chose Qmax as my provider because they worked well with outlets supplied by SingTel and StarHub. Unfortunately, both Starbucks at Ion Orchard and the Coffee Bean at Bishan Junction 8 have inexplicably adopted M1 over SingTel, and Qmax is no longer listed as a provider.

My mum had a phone with M1, and the experience taught us to never use them for anything serious again. I suppose this is their way of seeking revenge :P.