I think you've already gotten the two best pieces of advice: Make sure your enlarger is bolted down solidly, and get good lenses. Those two simple things will outweight any quality advantage of switching to another enlarger. (As to lenses: Test them. Every manufacturer makes a dog occasionally, and if you're buying used you have no idea what the previous owner might have done to the lens. But if you're buying used then you can afford to buy a few before you find the one that you want...and you can sell the rest off for a few bucks.)
If you don't already have it, a D2V head for your enlarger would be a convenience. It allows you to move one of the condensor lenses around when you change film formats, rather than having to replace the condensor assembly.
I've got a D2V and the truth is that I can get any part I need for it, either new (negative carriers, lens boards), by scouring eBay for parts, or for sale online. If you haven't already, check out
www.classic-enlargers.com - Harry has every part you could possibly need plus he can answer just about any questions you have.
If you really don't like throwing in different filters for VC paper, then a color head would be a nice convenience. I haven't found the filters to be onerous enough to justify the expense of a color head, but that's just me.
All in all, it's going to be hard to beat the enlarger you already own at a reasonable cost. If you go out and pick up a new, autofocusing, computer controlled, do-everything enlarger, all you'll be buying is convenience. The enlarger you already own is capable of world class work. The lenses and the stability of the enlarger are the only things that could hold you back. Everything else is just icing on the cake.
Be well.
Dave