Digipaks are a fine packaging method if you don't go with a manufacturer who cuts their costs on materials. Most JP releases are with digipaks and I've never had the glue/disc/etc issue that we get with the NA/UK releases. I'm surprised ATA doesn't raise the price a tiny bit to utilize better materials for "collector's editions" especially with the screwups they've had lately.
No doubt, I actually in general like digipaks, but like you said only when done correctly. The backing for the digipak in my opinion must be high quality. When you use flimsy, cheap and/or thin card it becomes an issue as it doesn't go well with the hard and rigid plastic trays that house the discs. What you find is that the trays end up breaking away and falling off, or you feel like your going to bend the card every time you try to take the discs out.
It also doesn't help they Anime Limited in general tend to use weird mechanisms for taking the discs out. The Patema Inverted UE set for example has springs at the bottom edge of the tray that you have to
push the disc towards for it to eject out. Maybe that's just me, but I tend to dislike those types of finicky mechanisms.
I own the Beez Gurren Lagann DVD set for example, and the digipaks there are really solid, as is the digipak for the US Gunbuster DVD set and such. Even Anime Limited's very own Kill la Kill release was pretty solid overall. I've echoed to Anime Limited my sentiments that I'd rather have a standard amaray (maybe a different color other than Blue) in a rigid box over a crappy digipak if you can't do them correctly. I own the Japanese Gunbuster Blu-ray set and I think it looks pretty awesome and wouldn't mind future sets looking like so:
Like you said, the Japanese sets generally have no issues with this and they release quite a few sets that utilize digipaks. I own the Haibane Renmei and Lain Japanese Blu-rays and they looks pretty awesome and are most importantly solid in build.
The famous Lagann Japanese/US set is also hefty (you could kill someone with it!) as is the Garden of Sinners set. The Japanese just get it right 9 times out of 10. Funny thing is as expensive as the Japanese releases are, a lot of them are just different colored amarays (usually black or white) in a rigid box, but you know what? They look cool and are solid with awesome artwork and that's good enough for me.