Anyone have experience with Sigma 105mm 2.8 macro vs Sony 100?

I don't have the Sony 100, but quite recently I acquired the Sigma 105, it is a nice lens which has the benefit of being a new design, it does not extend and has some weather sealing in it (splash proof or something like that), without forgetting of course the HSM which might not be a deal breaker as the focusing might need to be made manually. The Sony is a Minolta with a slightly different design which makes it quite old, have you thought about the Tamron 90 USD, it is weather sealed and does internal focusing too.

Im considering the sigma as well, good reviews and has OS and some kind of weather sealing, might be really useful lens. Price is good at the moment too.

Are there two Sigma 105 OS DG EX HSM lenses? I keep seeing widely different prices (new) and the Sigma I'm looking at definitely does extend during focusing.

http://www.henrys.com/65922-SIGMA-OS-105MM-F2-8-EX-MACRO-SONY-MT.aspx#prodtabs-1

I only have the Sigma version but its fine, as has been pointed out the newest one does not extend and has OS and weather sealing - I've not found a benefit of the OS vs IBIS in my A99 but either one works well (both together doesn't though!)

It feels a little plasticky and the switches don't inspire confidence but optically it's great.