In Jaguar (OS 10.2), there is an issue with a couple of skins with the new version. So if you do try the new version & see a blank window, change skins to solve it. Unfortunately this is a Java issue. It can't be solved unless you upgrade your OSX. But changing skins is easier & you can downld extra skins anytime anyway.

I can assure you LW 4.8.1 was a far better version than 4.2.x
From my experience in OSX, LW 4.9 was not so great. But LW 4.10+ seems to be very good for the extra additions & pleasing search improvements. Also a dynamic "learning" junk filter. I've been using LW 4.10 or 4.11 beta happily. The only complaints I've had were ... well it's documented in the beta section ... but these gladly haven't been permanent problems. But except for that, there's dramatic improvements that made me come out of my 4.8.1 cave to use the recent version full time. IMHO only. But as I said, if you have issues then I can help you out in solving them or going back in versions to at least 4.8.1