Just installed V. 188.8.131.52 on my 8700g, the installation went smooth, took around 45 min incl. backup & restore.
First reset for the device after the installation went so slow & there have been some gprs activities going on, which seems to be some applications updating the network configurations after upgrading.
After couple of resets, the device started to work so smooth without any problems.
The main enhancements noticed on OS. 184.108.40.206 were:
1. Better display over all (tried it on on Iphone theme & Dimension Zen).
2. Menu displays Ex. address book, messages are better displayed.
3. Browser got some enhancement in terms of display & performance.
4. New added applications (Word to go, Slide Show to go & enhanced voice notes recorder).
On the other hand, there were couple of negatives over all (Not for me personally):
1. In the Status menu, the over all memory size disappeared (not a big deal on 8700 as it's fixed memory).
2. Facebook application just disappeared of the menu, so probably there's incompatibility with it (will try to download & install again).
3. Mini monitor application keeps displaying errors & freezes (got it removed).
4. When downloading OTA application of the phone, got couple of time messages that it require V. 4.2 or higher (Which means it's not totally certified on all OTA browser detection engine, a solution might be installing over application loader to by pass the tests).
Over all i feel it's pretty much stable OS in my opinion & with couple of nice features & enhancements added to it.
I'm still on the second day of testing, if any further errors or problems appear, will keep you posted.
Hope you might find this information helpful.