I have exactly the setup you are considering- MLD's Supermid and inner net- as my larger "group" tent. Using this tent is about the only time I break out the LuxuryLite hiking staff since with an extra segment it is the perfect center pole for 'mids like this.
My wife, daughter, and I just lived it it for a week or so while we car-camped across several national parks earlier this month. For three adult ultralight hikers with gear I think it will work quite well, with the usual caveats about durability/condensation/etc of ultralight tents. (It is certainly a palace for two.) The inner net keeps your precious down bag off of the tent wall, but if you pitch it high off the ground you can definitely still get some spray from raindrop splashes, as I ably demonstrated recently.
I'm one of those- along with Henry Shires IIRC- who don't believe that you really need a footprint. Most damage to the tent floor is likely to be pinholes, which are easily repaired with a dab of SilNet. And, on the recent trip I mentioned above I did have a small creek flowing under the floor of the inner net tent on a couple of occasions with no leak through whatsoever. The tent is pretty new, though, so I can't testify to long-term durability. (I'm the only guy I know who can go on vacation to a desert and have it rain EVERY DAY that week.)
But, as a car-camping option for the wife and daughter it leaves a lot to be desired. I'm now in the market for a nice, big, dirt-cheap Coleman tent for such occasions...