I can't help with the arm differences but I did have a 9 on my MMF 7. It is a decent arm but probably not useful other than on a Music Hall or Pro-ject table. It seem to hold settings very well. VTA is a bit of a hassle but no more so than a Rega. I really liked it combined with a Shure V15VxMR.
The SE does not have wood plinth as you may be thinking. It is a verneered plinth, probably over MDF, so the difference is cosmetic only I would suspect. I'm not sure if the price difference is justified when you add things up but I do admit I have not heard the new SE. If you're handy you could probably get a used standard MMF 5, rewire the arm with Cardas wire and clips, change out the jacks for some really good ones and mount a new cartridge and be way ahead sonically and financially.
Just my opinion.