In my experience, Hi Space made the flimsiest and least reliable MD and CD-R media. Their 24k gold CDs were a joke. Some of surfaces were as irregular as rippling bathwater. Even the smooth ones were problematic -- I've never dealt with so many write errors in my life. I even began to doubt my Yamaha burner until I switched to Quantegy.
Hi Space's packaging and product were often beautiful, so I was always sad about hating them. But just today I was placing a clear HS MD in my N1 and thought: The shuttle's so fragile it's a wonder this plays at all.
I'm not trying to contradict anyone here, especially since Hi Space vendors always touted their durability, too -- there's the question of a greater consensus. But the DJs I know *never* use Hi Space for recording sets. And I've read of HS unreliability many times on the MD newsgroup and on MiniDiscussion.org.
Personally, I like TDK and Sony best. Axia and Denon seem fine as well. The shuttles on older Maxells were problematic and clicked in some players, but maybe they've fixed that by now. You'd think so, right?
Neige discs look great and come in really convenient cases that sit in your shirt pocket like cigarette packs. But the only two kinds of MDs that have ever failed me were Hi Space and Sony Neige. Most of my Neige still work, but all of them should, since recording/naming MDs can take time as well as money.
I've never had problems with the two Memorex MDs I own, but at this point, you can get a box of ten 80-minute TDK Music Jack 2002s down the block for $14.99 including tax. They look great, have real jewel cases and last forever, so why settle for Memorex MDs in nasty cases?
HHB looks great and they're trusted in many other areas. But I'm sorry, I refuse to pay three and change for a single purple MD.