I find a good few coats of DD SN matches the longevity of AG EGP. Havent tried Colleinite, but beleive it to be the hardest wearing stuff known to deatilers If you want maximum longevity, go with Collenite
Not used DD SN for long enough to say but I'd find it hard to see how it can last as long as AG EGP - that stuff lasts forever even with plenty of washes! That said, I'd say the longest lasting of the lot of those is the jetSEAL. The Zed still comes up a treat with it and is lauded by many on DW.
Maybe its just because AG EGP doesnt bead as nicely as DD I assumed it had worn off. Beading is usually the only way you can tell wax is still on there and working, so I guess i assumed the EGP was dead, but maybe it was not
Try the red mist... never seen anything bead like it...