If you have the budget for both, get the MH20 in the group buy. Use it for a few weeks or so. Then if you still really want to try the Zebralight and think you'll like the Zebralight interface, then go for it. Then you can really make the comparison between the interfaces and may appreciate the interface of the Zebralight more if you like it.
If you only want to get one, and are reasonably sure you may like the Zebralight interface, I'd say just get the Zebralight and be done with it.
My first light was Fenix E12 but was unsatisfied. Then I did tons of research and was sure I'll probably like Zebralights so I ordered the SC5w. While waiting for it to be delivered, the Thrunite TN12 2014 went on sale in a local store for a good price so I bought it and liked it. But as soon as I got my SC5w, I stopped using the TN12 despite the raw lumens difference. I didn't like how the TN12 had 5 levels to cycle through and it quickly gets tedious to switch modes. Personally, I've now basically stopped look at any other lights but Zebralights.
I'm currently debating between Zebralight SC63w or the hi CRI SC600 MK3 that's supposed to be out sometime in summer. I know I really *should* get both. :nana: