Some freeware can be better than many commercial alternatives, and other freeware is absolute unmitigated crap that isn't even worth free. Linux is a prime example of how good free software can be.

Best thing you can probably do, is set up a small test area. Maybe a few systems that you could afford to be down for a day or two if necessary. Try the program out, see how it works for what you need. If it seems to work well, you can gradually add more and more systems to your testing sample until either you find it won't work for your needs or you feel confident that it will and can migrate every system.