After playing alot with 2.2 I can say that I liked the fact that there was no save game feature, because it made things interesting on the smaller and easier maps.
Here is what I think -
Ironman mode is great for the smaller and easier maps, because it makes them thrilling, unlike the simple crashsite missions from X-COM (which were very boring after a while, because you could save all the time).
Even this concept is great for the simpler missions, you can't keep it for the longer and harder missions (which I hope you are planning) because, as many people stated before, it gets quite hardcore. Imagine doing the cruiseship in Terror From The Deep on Ironman mode.
My suggestion is to enable some checkpoints on the larger and more difficult maps, which would enable the player to go back to that position, like in a platform game. Reaching the checkpoint before someone dies could be an extra challenge, and you can play with that too.
I'm saying this because as the game is designed right now, it's really hard or even impossible to play it on ironman (ie if half of your best squad dies, then that's it and you'll have to deal with it), because there are so few replacements and all of them are below average.
Then, if you really want to keep the ironman feature, you should provide much more soldiers and better than average skilled.
As many others said, and I agree with them, it's quite unrealistic for a top military organization to rely on a bunch of average GIs. There is hard to find one that has at least one proficient skill in the recruiting window, and even that one has poor accuracy or mediocre TUs....
Besides, I think that most players would like to make a squad of "heroes" and go with that squad until the end of the game. I remember some of my 1st top squad names, like Arthur Parker, or the two Iakubiks I had... and I'm sure that many can relate to this. I haven't abused of the save game feature, but it was useful mostly when something really stupid happened which killed 2 ppl or more, like a bug.