if u ride mostly on water, why do u bother to buy a foil and spend money for the few times u ride on snow? u might have some downside but u save some cash.
if u ride mostly on snow and with a Mtb in summer, foils might be a good choice.
open cells foils can be fast and hard packed for trekking ( no need to deflate) but have less depower but can be landed or relaunched fast .... closed cell foils need to be deflated by pushing the air out ( so it s a tad slower than the open cells) but have better depower and turning speed.
if u ride 50/50, some peeps pick closed cell foils ( peter lynn/Flysurfer) so they can use and feel the same behaviour whatever the season.
LEI have a better instant depower for gusty conditions but the wind range is the end, pretty much same as their closed cell foils counterpart (i ride both from time to time.), open cell foils have less depower because they lack the rigidity of the 2 other types.
now for performance, u can do newschool moves with open cell foils ,just as much as with LEI kites so it way enough.
riding LEIs on snow isn't much a problem if u have deep snow but if the snow is packed or hard or if u ride in some backcountry region, u might encounter barbwires, trees, (stupid other things) that migh just blow the LE...
like i said, a matter of taste (and wallet), u have advantages/downside in every type of kites.
When I snowkite, my first choice is my open foil (Ranger), but only if the wind is relatively steady. It doesn't need to be super steady, but the Ranger doesn't handle the super gusty conditions we sometimes have on small inland lakes. When it's super gusty, I'll switch to an LEI. My Convert handles gusts much better than the Ranger. Since the Ranger is an older design (and the only foil I've ridden), I can't say how newer designs would handle gusts.
The big advantage of the foil, for me, is the ease and time of setup/launch/land/pack-up. I often have just a short amount of time to kite (after work and before dark-thirty). If I have only an hour to work with, saving 10 minutes is significant. With my foil kite, I'm riding 5 minutes after I walk out onto the ice. Even my easiest LEI takes more than 10 minutes to set up. I know that doesn't sound like much of a difference, but there's also a pack-up difference (quicker with the foil), and the combination is significant to me.
In reasonably steady wind, the performance between my foil and LEI's is similar, so that's not a determining factor.
Once one pump was perfected I ditched my foil quickstyle.
I like the familiarity of the LEI from using it all summer and fall. It's nice to just have a 3 kite quiver. I don't find the setup in winter too bad with the LEI. We usually find a wind protected area to setup and then walk out to the wind.
The depower, wind range and gust handling ability of my gk's is a godsend for the crappy winter wind we get.
I fly LEI in summer and Foils in winter... and foils hardly show any wear. No pumping, no plastic to break, easy self launch and land and leave lines attached all winter. I find foils much easier to deal with and teach with in the winter...
Keeping an LEI in good shape for water is very important and I don't want to wear it out on the snow ice in winter. Almost like having to type of tires, summer and winter. Use what works best for the conditions.
But if you can afford both and most focus in on water LEIs work great.
When you get to try both, you'll figure out your own preference too..
Here is fun day on an Ozone Frenzy 7m Foil Snowkiting Snowboard mostly flat but lots of fun.