Here's the only way to answer that:
What will you do with them once you open them, and what kind of packaging are they in?
I'm a poser. 90% if the fun of toys for me is finding that perfect pose for each one, grouping them with other toys, and DISPLAYING them. I love Lee, but I'll never understand the mentality of opening toys just to stand them row upon row, feet firmly planted, one in front of the other. The only toys I don't open are the ones that I'm COLLECTING, not even for resale, but for their collectible nature, such as con exclusives.
Now, my point about the packaging... if they look great in the package, and the package brings something to the party, keep em in package. If I'd had the money and inclination to get every Marvel Select figure, I'd have one of each still MiMP on a bookshelf, and then the few that I really loved opened and displayed. As is, I bought them mostly to compliment my Legends collection and as such, have opened those I got.
Ultimately, my question is, how are you going to get the most value out of them? By opening, posing, and displaying, or by keeping them packaged on display? I know the answer for me, but it isn't the same for everyone.