I check BB Leaks, crackberry and so on, for the Storm 2, it is 126.96.36.1995 officially released by Verizon, but be ware the bedside clock doesn't work. There is a way to install the bedside mode from another web site, and I have done it, and it works.
Which OS are you currently running? You'll get different responses on each OS as everyone seems to have different experiences with each one. I have OS .607 and refuse to upgrade to the newer ones because my storm 2 runs flawless on it. Others will tell you this OS is terrible. But quite frankly, you need to choose one and try it...you can always wipe the device and load another OS. go to www.crackberry.com and click on the forums. There is plenty of techies in there that are more than willing to walk you through the process.