Maybe cuz I just have trouble adjusting my vocabulary, but I still call em "doorway" pages hehe.
I recognize the difference but it's just habit that I refer to them as such.

One thing you can definitely get in trouble with and that do you no good are the automatic redirect doorways which used to be the thing to do back in the day (year ago).

I find that so long as a "doorway" or "gateway" page has real substance in which the keywords and links are found, they work quite well.

Those auto-doorway creators can be trouble if you rely on them too much. Creating your own doorway pages with html links and good anchor text keywords can do ya a lot of good but as you pointed out, the key is to make sure they actually are meaningful pages. Substance. Real stuff to see and read on them.

Of the 12 sites I'm focusing on with SE placement right now, I've seen on average, pagerank jump from 3 to between 6 and 7. And I think the doorway/gateway pages have been a big part of that.