I have yet to try the push button OS reload, so I'm glad to see it works well.
I have however extensively used the rest of their features, including the private network IPMI and remote IPMI reboot / power cycle. They even have a nifty little WAP portal, which I can use to power cycle servers from my phone.
It's nice to see such innovation in a market that seems pretty cut and dry (you get the box and the bandwidth, and maybe a remote reboot port if you're lucky). Hopefully other providers will follow, and SL will improve their support staff.