I have to be careful with lentils, dried beans and split peas, because I can overeat them (just as I can overeat just about any starchy veggie, even one so high in fiber and protein).
That doesn't mean they're the devil, it just means I can't see them as an "all-I-want-to-eat" food (but there aren't many foods other than iceberg lettuce that fits that description anyway).
I have learned to make my soups thinner though (my grandmother's split pea soup recipe was so thick it almost looked like green mashed potatoes).
My absolute favorite lentil to use is the tiny orange variety. I also love using yellow split peas. I actually like that the lentils fall apart into mush (but this also makes them higher glycemic, which is probably why I find them so addictive). If you don't cook the lentils that long, they're actually lower glycemic and therefore filling longer.