Maybe I am bucking he trend but I'm a very happy customer of slingshot.
I am on the unlimited plan and apart from a minor delay when signing up it's all been flawless.
Good line speeds (Possibly related to all new wiring in my home), streaming services are working well and latency is pretty good for gaming.
I'm a bit more technically inclined than most of their customers so I've never needed to call their helpdesk, but so far I'm pretty damn happy (been a customer for >4 months).
If they are doing any form of rate limiting it's barely noticeable for my usage.
Keep up the good work guys.