Hi,
interesting that you mention HW.
I am testing VSTi stuff on a comparably weak P4 system - compared to todays core dual quad standards - too and I have to say than many problems are system configuration related.
On PC's there are too many processes running having nothing to do with making sound... kill them all and you get much better performance and reduce trouble to zero.
While discovering that truth - don't run music software on your office PC - use the best machine you have availiable - I ask myself what the difference is to hardware... as you need best a dedicated PC for music which is hardware cost too.
Some guys say PC sounds bad... ok, but it does sound great if you use a really great audio interface...
Some guys say PC's have latency... well, forget that if you have a PCI based audio solution, that's fast, just dump the USB or FireWire stuff...
This list can be continued, the point is so much trouble with PC is simply because it is not easy to configure it well for music making and if you will find that you should not run your office software or web broser on it... AND... if you have started optimizing you'll find that this hardware isn't really cheap then...
So beware blaming software for issues it can't solve and come back to those issues only related to the programs itself - which is, of course, sometimes hard to figure out...
...finally, using a keyboard workstation may be restrictive but it works right out of the box, so it isn't an outdated approach for those who want making musik instantly on hardware that simply works.