I used to buy this when it was coming out (Back then, comics were cheaper. Boy, I miss those days.), and I thought that the first year or so (Heroes Return.) with John Romita Jr was really good. That Destroyer arc was the best, as I really did not know about the character before then, and that made me really dig him. After that, there was some good stuff, but it started to lose steam. I think that Jurgens should have left a lot earlier (Say, after the death of Odin.). Overall, I think that Jurgens was underlooked, and I would classify the Dark Gods storyline as a classic. If just for the first year, I would give him either a B or a B +, overall I would give him a C or a C-.
The first two issues were amazing. Added some very cool new characters and some great set up for plotlines.... but he would start a great idea and seemingly lose interest and have a crappy and illogical resolution.