Boondoc, I upgraded to v6.0.9 and regretted it. Many errors using my C-II printer, the TSP 800. I asked tech support for help, and was given numerous "fixes" which did not help at all. I literally couldn't print ANY C-II's. Then Bert gave me a work around idea that kept me operational until v6.1.2 came out.
Since upgrading to v6.1.2, the TSP printer issue was actually fixed and works perfectly fine now. I can understand your hesitation to upgrade, but the v6.1.2 is working quite well and I would dare say that it is on par w/ the old v5 as far as functionality goes.
If you are not reporting MU data to CMS, you don't have any extra hoops to jump through in v6.1.2. You can simply leave the MU buttons unchecked. It will work the same. But if you have no plans to use MU, you may not want to bother upgrading. The only likely issue is that customer support for old versions will, in time, become limited if you choose to stay with an outdated one.