I doubt that you're getting true square grind geometry on the H.F. grinder, If you are, I know quite a few people that would be interested...Can you post a cutter pic?
I've decided to make the switch over to square, but then I am cutting in clean conditions for the most part.
I felt like it offered a substantial enough performance advantage to make the investment in a square grinder.
I'd still keep a couple of chipper and simi-chisel chains handy when you know you're going to be in dirtier conditions
I tried Square filing, but never really mastered it before I got the Silvey.
Keep in mind that properly sharpened round will outperform poorly sharpened square every time. You might
consider buying a loop of square chisel and buy a $10 square file to maintain it before diving in headfirst.
You will will have to make the decision if it's worth the extra trouble. Plenty of good info / people on here
that can be a big help.