This baby on the bottom is called the Nexus which is a two piece Tungsten/7068 Aluminum top and it's capable of getting 30+ minute spin times but my record with it is 27 minutes.
To get the best spins you wanna make sure you spin the top vertically as straight as possible and make sure the lens you're using is slightly concave with a coating of oil from your nose or forehead.
:sigh:
I haven't been following Billetspin because the tops are (quite) a bit too expensive for me
and I am more interested in maximal spinning time than maximal artistic look. However, I could have justified this purchase, if I just knew about it. I didn't know and now they are gone.
I hope Rich finds a good solution to the balancing issue and releases another spinning time optimized top somewhere in near future. And, of course, announces it via email list (subscribed now). I am not in facebook and it seems that most of the communication is done there. The group is not publicly visible. For example, the webpage says that the next top is launched in less than a day (22 hours and counting) but there seems to be no information about the new release, no information about what will be released. Just the release time.
Anyway, I have a lambda top, the older standard version (aluminum + brass) with a ruby. It is on a slightly concave mirror on my desk and every now and then I spin it. I used to measure the spinning times when the top was new and the spins varied between 8-10 minutes, with a maximum of ~10:30 or so.
The mirror diameter is ~16 cm with a magnification of x3 or so. Three legs ("suction cups") make it stable. I used to dream of a stone spinning base, perhaps made of granite. However, mirrors are pretty good looking and cheap and I doubt that there would be any noticeable difference in spinning times with harder surface material. Glass is also safer for the ruby so I am happy with this solution. Should buy another (smaller) base though.