I'm pretty happy with it. I'm using it with Cox cable internet.
I don't have any software installed for it. I just plugged it in, called Cox, gave them the MAC address, etc., and it started working.
I do have some occasional instances when the internet seems very very slow. I unplug the SB5100 for a few seconds, then plug it back in and let everything re-initialize and everything seems pretty quick again. I may install the Moto software and see if there are some diagnostics or something that'll give me a better idea of what's going on.
I purchased mine at [link|http://www.newegg.com|http://www.newegg.com] - [link|http://www.newegg.com/app/viewProductDesc.asp?description=25-122-104&depa=1|$65.50]. I wouldn't rent one even if I only needed it for a few months (you can always sell it on ebay). IIRC, Broom recommeneded it, and it gets good reviews.
HTH.
Cheers,
Scott.