I've been fishing with the Shimano Sustain 4000 for the last 6 months. (I've not fished the Abu Garcia model.) I am extremely impressed by the smoothness of the reel (try spinning the handle of one in the store: goes around and around), and find the drag is good, too: taken saltwater speedsters of up to 20lbs on it w/ 10lb line.
I've had one major problem and that is the amount of line twist I get after a fish has taken out line against the drag. (No, I'm not reeling when the line is being pulled off and I don't have this problem with my other spinning reels either.)
I took the Sustain in for servicing and the technician told me the roller bearing was fine. I was told I shouldn't be having this problem. I was so annoyed I called Cabela's and they agreed to take the reel back (despite its being 4 months old at the time!).
I decided to give the Sustain one last chance before boxing it up, and took it fishing against the top end Daiwa spinning reel (forgot the name, but it looks very similar to the Sustain and costs almost as much). Well, the Daiwa was a good reel but the bearings weren't in the same league. The Sustain 4000 was so smooth and fun to fish with I decided to keep it after all -- despite the line twist.
On my most recent steelhead trip, I'd simply cut off the leader after every good sized fish and fed 50-100 yards of line downstream with the current to take the twist out. I then reeled up and re-rigged. (I also changed line completely every-other-day, and ran the line out, too, to take out the twist before fishing each day.)
Certainly an annoyance, but overall I still rate the reel #1 in my stable as it's a pleasure to cast and retrieve. But would I buy a second one . . . probably not (unless the line twist problem is specific to my particular reel and/or your query doesn't turn up any suggestions of 'perfect' high end spinning reels). With the hassle factor included, it certainly isn't 'value-for-money'!