Personally, I won't engage their service unless I really need their help, otherwise, I won't even call to ask their hotline. This may differ from one person to another.
Yes, if you take the Lite plan, you will get $100 discount to offset your handset, and $150 if you take Reg plan. I am one of those ppl who ported from Stinktel to M1, for a very simple reason, price. M1 LG G4 handset price with contract is the cheapest and I could get the $100 port over discount, while I wouldn't get any discount whatsoever from Stinktel even though after I called them to ask for a voucher. So, since they did not want to retain me, I moved over, bye bye stinktel.
Connectivity wise, so far, my experience has been good. Been getting LTE most of the time without issues and quite fast & reliable speed.