I had an Erma 85 until recently. My experiences were that it is, just like the FN 150 (of which it is pretty much a copy), a very good gun to shoot with. The trigger on my gun was excellent, and it came already with Nill grips installed.
There are a few areas to watch out for, though. Noe that these observations are only from .22 versions. No experience with .32 on this gun at all.
1.) The trigger gets gritty pretty fast on some guns. Mine had no issues with this, but I heard of several people who claimed they have to clean their gun every few hundred rounds to keep the trigger smooth. Best advice here is to use some 'clean' ammo, especially when shooting .22LR. CCI or Fiocchi were pretty clean here, it seems.
2.) Trigger adjustment is far from easy. I can only say little about it, as I'm pretty much a novice when it comes to hand guns, but unless you got someone close by who knows his way around the Erma, stay away.
3.) The material used for this gun is not the best. I've personally seen some guns that developed distinct markings around the chamber (where the slide strikes against the breechface). These were, however, guns that had gone several tens of thousands of rounds. Best advice here is not to use too hot ammo. Mine worked very well with CCI SV and Fiocchi Maxac Soft.
4.) The sights are not too stable. Best not to drop it often, and the threads can wear out fast.
5.) Erma does no longer exist, and even in Germany there is only ONE supplier of spare parts ( http://www.asamnet.de/~ehrenred/ersatzt/esp85.htm
) and they are pricy! plus their stocks are dwindling...
When what I said scares you, don't be afraid. I know many people who own an Erma ESP85 and are happy with it. You have got a pretty good gun.
Looking back on it, and seeing how my Erma worked reliably all the time, I almost regret trading it in for a Feinwerkbau 93. That is, until I get mine back from the factory and it works ;)