The stuff I'm saying about using higher-end mat cutters and avoiding precut mats applies most to those who want to publicly exhibit their work and sell it. Presentation is literally something that will make or break you if you have those ambitions..so don't pinch pennies. None of this stuff is really super costly, not like a new Leica lens.
If you just want to frame pics to hang a home or give to family or friends, then precut mats (as long as they're the archival kind) might be fine, and cutting your own with a cutting system that's hobbled by the manufacturer (by lacking basic stuff like the squaring arm) will still give great results (but at the cost of more work to get those results). That's why I tell people who want to exhibit and/or sell to avoid them. If you cut a lot of mats, the limitations will begin to really bug you because it'll slow down your workflow, and framing is gruntwork anyway. I don't do it for fun, cause it isn't. I do it because frame shops are bloodthirsty with their pricing and I have always been disappointed with the quality of mats I didn't cut myself...and I am very obsessive to a probably unhealthy degree...