I'm on Teksavvy and so far I've had zero issues. Went with the 200GB cap since that's all I really pull in a month, plus apparently its 400GB averaged out over 2 months and there's rarely 2 months where I exceed 200GB. Plus it has better routing apparently so lower ping times.
I grabbed my Speedtouch 516 from Infonec as it was cheaper than TSI. Works great and I've had no issues so far. I use it in bridge mode so it really isn't doing much like DHCP/Firewall/etc. My router can handle all that.
I hope you know about DSL Reports:
TekSavvy forum - dslreports.com broadband community
Great place to ask any questions you may have.