Getting the feet out of toeclips (without cleats) is easy. Just push the feet down and back, and they pop out. Loosening the strips really only makes it easier to get the feet back in once you start rolling again.

With toeclips and cleats, you can also generally do emergency extraction, similar to clipless by twisting the feet.

I think toeclips do help the learning curve for clipless. If you like toeclips, you'll love clipless, and the transition can be quick.

If you can't get the hang of toeclips, then you may not want to go clipless.

As far as benefits... there is a lot of debate. I do think the clipless is better for instantaneous power surges. But, some data indicates they don't help a lot with overall efficiency.

I hit 160 miles Saturday, with a late start, riding until quite late (or early). My thoughts is that the clipless cleats (SPD) keep the feet on the pedals and turning as the legs might have been too tired to do so.

Going from toeclips to clipless, I decided I didn't need flats, and went with basic double-entry SPD, and couldn't have been happier. Or, in some cases, single-entry SPD for a bit more aero look, although perhaps not much actual performance gain.