Indeed I have. Well it is fairly basic as far as conversions go, but i'd only reccomend doing it yourself if you have a solid mechanical background. Benefits... well the DE is twin cam with a few extra valves, so does breath a little better, and doesnt have any flat spot like the E. I think it feels more tourqey too. Economy wise it is pretty much the same as the E. Power wise its also similar, its not a huge step up, (roughly 105hp in stock form, compared to 95hp for an old stock E)
Really... unless you plan on getting the engine worked with cams and headwork, it doesnt make it a worthwhile swap in NA form.
Turbo however is a different story... you will find it much easier to buy off the shelf manifolds and equipment from the US than ever possible for the E. And will provide more power than an SR20DET at similar boost levels. All up for the transfer to a turbo KA-DET budget maybe $3000-4000 doing a fair bit yourself.
If you want specifics do a search here, i'm sure i've put out more depth before, if you are still serious and want any further info PM me.