DAT was indeed successful in professional studios and in broadcast operations. I recorded a lot of music using DAT machines - both in-studio and on-location - when I was at WCFE-FM, Mountain-Lake Public Radio in the early to mid-1990s. I don't recall the brand or model of the DAT recorders we had, but they were far from foolproof. In fact, they were downright squirrelly little monsters.
Not in my experience. I had a portable Tascam, (two channels, XLR inputs and digital output), that never failed. I used it both on location and in studio and my locations were rough stuff as I filmed naturalistic documentaries. The only problem was the duration of the battery, that I solved buying three packs. Though the old analog Nagra was superior in term of engineering, solidity and sound quality, the DAT was great in term of facility: lightweight and cheaper. And those Nagra's reels were an hell to carry and to preserve and to mount and unmount, compared to the small DAT cassettes, expecially if you are on a Zodiac recording whales' breath.