Just wondering how it sounds… and whether or not it’s just overkill.
Overkill is GOOD! You’ll never know unless you try it. If I had an SE-1 or 1x, I’d try it myself! Once I get the 101, anyway. 
musiciansfriend.com has a 45 day return policy…you can decide for yourself if it’s overkill
(either that or look for a used one on craigslist…resell it to get your dough back if it’s not for you)
Beware of those hassle free return policies…and beware of anything coming from Musicians Friend lol.
Eric
Man, I’ve got a horror story about MF/Sweetwater experience. I’ll spare you the details. It has to do with an Ibenez GAX-70 Transparent Red guitar, so that’s all I’ll say about it. 
NEVER AGAIN! 
An MF-101 with the SE-1(x) would probably be a bit redundant since that synth already has a Moogish sounding filter. You would get some unique tones though by using the synth Oberheim filters through the MF-101. It would work better if that synth had a “Mix Out/Filter In” insert jack for an external filter along with a Filter Cutoff CV Out jack.
I use my MF-101 with another synth that I modified. Check this out:
I have to disagree here. Many Moog users run their Moogs with authentic Moog filters through the MF-101, which is also a Moog filter. There are some unique sounds to be had with such a setup. That’s awesome what you did with the G2X, by the way. Sounds like something I would do.
Thanks!