I'm trying to decide on a printer to purchase.

I've had 2 Monoprice Maker Select v2 which unfortunately both had problems within the first 30 days. One had loose/broken wire to the heater cartridge and the other came with a bent frame and rattled a lot during printing. Since they were within the return period I decided to return them and look at my options.

I spent a LOT of time printing on those printers and tweaking everything. I got pretty good with the various slicers I used. I've got tons of stuff around the house I printed and I'm hooked on this. I've been searching for weeks at this point for best printer to buy as a replacement.

Some notes about the i3 design that bugged me:

1) The movement of the build plate inevitably lead to rippling in the prints. It looks like echos of any sharp turns in the design which require the bed to move. This meant I had to slow my printing speed down to reduce this effect.

2) There seems to be a lot of vibration in the frame generated by moving the bed and extruder around at the same time.

3) I could print faster on a z bed design. It was kind of discouraging how long some of the prints took on the i3 design because if you speed up the print speed too much the rippling becomes much worse.

Other than the artifacts in the print surface, I was pretty pleased by the quality of the prints from the Maker Select v2. It was pretty loud though.

I've done tons of research and it seems that the answer to the problems with the bed movement are solved by beds which move only on the z plane. This got me looking at the Maker Select Ultimate.

But then I found the CoreXY design which also only moves the bed on the z plane. I am having trouble finding a complete CoreXY kit, though.

Then I saw the Maker Select Plus, and thought maybe the added weight of the control box being in the frame might help reduce some of the frame vibration?

Finally we have the Prusa Mk2 which everyone raves over, but I worry about the amount of printed plastic parts and it still has the moving y bed problem. And the bed isn't metal. Does it warp more than a metal bed? Also, it seems like I'd be able to get better speeds out of a z bed design without having to worry about rippling.

I'm definitely up for building a CoreXY if it's that much better. It seems to be, but I've never used one. If I can't build one for less than the Maker Select Ultimate, I'd probably go with that instead. If I go with a CoreXY build, I think I'd want to have stuff cut in metal (Was it Voron or another version that was built to have the connections and stuff cut out of flat metal plates? I don't remember). But again, if it's more than the Maker Select Ultimate, I would probably just choose that.

What about auto leveling on a CoreXY? Important? Manual leveling on the MP v2s was annoying but looking back, not that bad. The leveling held pretty well over the course of weeks for the one that didn't vibrate too badly. And now they have those locking nuts on the Maker Select Plus, which I imagine would make it keep level even longer.

Overall, though, I think I'd really LOVE having a faster build speed. I got decent enough quality at 40mm/s, but when I saw how much faster it would've been at 60mm/s I just wanted to be able to go higher. (the rippling was pretty noticeable at higher speeds because of bed movement)

I've narrowed it down at this point to: Monoprice Maker Select Plus/Ultimate, CoreXY (D-Bot, C-Bot, Voron, Eustathios?), Prusa Mk2, Something else?

EDIT: If I can build a nice CoreXY for significantly less than the Maker Select Ultimate, that's probably what I'd like to do. It's just hard to narrow down which version to pick.

EDIT 2: I would want at least close to the 200mm x 200mm x 180mm build area that the Maker Select v2 had.