Hi!
"Hardware vs Software" is probably one of the most popular topics of discussion around here so search the archives and you'll find all the info you need.
Here's my $00.02 though:
Personally I use everything in my studio since it's only the sound that's important to me. NOt the high ratings and specs. If it works and sounds good to me I use it. Now, here's a couple of things that I think software synths are better at:
1. They can load and handle more samples. Gigs and giggs of samples.
2. Depending on the CPU of your computer you can run as many instances of different software synths as you like so the usual limitations like running out of FX and polyphony are not really an issue. Unless your PC is dirt slow of coarse.
3. Software synths and even software renditions of some very expensive hardware synths are much much cheaper.
So I don't think it's a matter of software synths being "just as good" but rather a matter of them being much much better and much much cheaper.
Speaking from a general perspective anyway. If someone really likes their real ARP 2600 and totally hates software there's nothing wrong with that. We all like different things.
EDIT:
Sorry, I've missed the word GM in your post. I think there are a few software GM synths out there but I can't really think of anything specific. A few weeks ago there was a post over at the General Arranger KB forum where a few people discussed software synths with General MIDI compatibility. You may want to post your question there.
-ED-
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A gentleman is one who never hurts anyone's feelings unintentionally.
- - - Oscar Wilde [This message has been edited by 3351 (edited 12-10-2005).]