Brissie's great - I love the humidity

LW don't exactly advertise the fact that once Pro's out of date, the free updates & support disappear. They could do better!

There are a lot of differences between the latest LW & 4.12.6...the biggest is that LW now supports torrents. You can have a look at the changelog here & see exactly what's different.
Lime Wire » Features History

If you're looking for very rare files, you might see a big difference in Pro compared to basic. And those couple of extra hosts to connect to can make a difference. It's really up to you to try the new LW but honestly, if I were you & wanted to update - I'd go basic. But, you have to remember that if you do reinstall a new version of LW, you'll lose the version currently installed. Do you have the 4.12.6 installer saved? If not, don't update unless you're prepared to lose that version.

The version of BS linked to in my other post is an older expired Beta version which works very well. I've never had problems with searches using it.