Jacks R Better No Sniveller!

It is VERY viable.

To reap the full benefits, though, I've found I need to be in temps where I wouldn't need to add a vest or jacket during sleep. I mean – if you have to bring one of those anyway, then the poncho feature is not useful.

It works great under FroggToggs or DriDucks, which are cut big. I look like the Michelin Man in it, though! I end up tucking the extra insulation into the rain jacket.

Side note: the JRB down hood is a great add-on, and I hope to add the sleeves one day, but have not, as of yet.

What about the Rocky Mountain No Sniv? More versatile because you'd be less likely to have to add a down jacket layer while sleeping?

What about under an Integral Designs eVent? Should I order a large if I usually wear a medium?