Well worth it and that's not all that much money. Software is a cost of doing business, you should budget ~$5k a year or so for software upgrades/new software purchases.
Absolutely worth it, X10 is a huge improvement over v7, tremendously more stable and noticeably faster. Handles transparencies and .pdfs better (not perfect, but much better). Run it in Windows 7 64 bit and load up on RAM, and install a scratch disk for Onyx and it'll chew through files like nothing.
I can attest to that being about right considering a couple of weekends ago I got back from an embroidery trade show that was local and I spent quite a bit on software. Changes happen all the time. Software I was using before the upgrades were top of the line, now other features even as simple as just work flow features are in the newer software.
10.1 fixed all our remaining PDF problems (we use the X-4 standard, as recommended).
Productivity is the key reason to stay near the edge for me. Time is the most valuable asset, anything which reduces task time is a win and most software upgrades have some task time reducers (I can't imagine still being on CS3...).
Getting a bit off topic though .
Got the upgrade to 10.1 onyx Friday. I'll get to play with it more tomorrow. However it looks like I still have to upgrade the Eye 1
Cause it seems to be stuck on 1 patch at a time instead of reading a whole row of patches at once.