Don't worry about it. You've bought a good quality machine and it comes with a 3 year warranty. If you will be the sole user you can eliminate the concerns about subframe vs. 3PH by using it cautiously and not horsing it around. I take it yours will come with a PTO pump that you will attach to your PTO and that will supply fluid for the hydraulic action of your hoe?
Try not to agonize over your decision; I read through the Liberty Corp. entire web site, and from what I can discern you should be good to go! Post pics of it all hooked up.:thumbsup: