I'm thinking of running EE in either the MD or the SB (mainly to deal with 1 drops like
Nimble Mongoose and
Mother of Runes). However, I'm considering dropping a basic Island for like an Underground. I don't want to splash and I'm not interested in supporting a third color. The advantage being that I can fetch into 3 colors for EE if I need to, but the downside is that my mana base just got weaker. There's really not that many problem three drops in the format right now other than KotR and Liliana, but Legacy is a wide format and it might have its uses. Worth the downside?
Also, I think I've ultimately decided that it isn't worth it, but I was looking at
Kira, Great Glass-Spinner (or
Mother of Runes) as a possible way to protect Stoneforge (and equipment holders). It seems like everyone is gunning for SFM and she's losing some of her edge. It might just be that Spell Pierce is all around more useful.
Another card I've been looking at again is
Spellstutter Sprite. I was one of the first to drop Spellstutter after the MM age, but now that one drops have finally re-established themselves in the format, I'm wondering if it wouldn't be a bad idea to pick up a couple. The biggest problem (and the same problem I've always had with them) is that they are tempo negative. One drops like to get played on turn 1, Spellstutter can't come down until your turn 2. You can hit their topdecked one drops sure, but it still doesn't help your early game. Still though, Mongeese like to come down once threshold is hit...
Another thought I had was that I'm not convinced
Vendilion Clique is as much the powerhouse that it once was. Looking at recent top 16's, the biggest reason I'd see for keeping them MD is the prevalence of Stoneforge. They tap SFM, cast Clique, and profit. However, it might be better to add more early game help so that we can reach our planeswalkers and a three drop sure isn't going to help against linear aggro and tempo plans. And then, assuming Clique is no longer worth the MD slot, is it then worth the SB slot? I'd be inclined to think so, but perhaps there are better bullets out there.
One last thing... Riptide Laboratory. Useful? I love it for it's cool factor, but realistically I think I can count the number of games I've used it on one hand. It might simply be better to shore up your colored sources or even run a miser Academy Ruins for either EE or equipment.