To make a short story long, my first expensive phono stage was invested in AI M3a + Goldboard, I didn't know what I was missing until I tried a ARC PH3, then I subsequently disposed the PH3 and tried Vendetta, Krell KPA, Pentagon (rare German), Linn Linto (very good), but finally, Groove is it. I also have the Spectral DMC20.2, which has a very good phono stage built-in, almost comparable to Vendetta, but I still prefer the Groove.
I think a part swap (PH3-SE) does not really do anything to the fundamental circuit design (contact me privately for what I did to my PH3 to make it better, but don't waste your time), the Groove is worldclass, noise is extremely low, and it melts the border between tube vs. solid-state. I can tell you that you'll not hear more information retrieved before. It is like upgrading from a digital camera to a Leica (Leica, not Nikon...) because it can truly bring out the color, the shades, the beauty in the recording. In fact, I am so glad that I can listen to 50's mono recordings and enjoyed them via the Groove.
I believe Mini Groove Plus has 90% of the quality of the Groove. According to the factory, Groove is like a 'mono-block' version, and Mini Groove Plus like a Stereo version, where 2 channels are on the same PCB, and share power supply, while the Groove, each channels has its own PCB and power supply.
One point about the Groove is that the cartridge loading and gain have to be specified and not user changeable. It is done for technical reason.
I have my current set-up posted in my web.