Some people like them
Some people don't
Reliability issues have all but been solved (unless you buy an older fork that has not had the newer seals fitted etc.).
I like them, easy to setup, easy to service myself, work VERY well for such a lightweight XC fork (well they should do with 150mm of travel!).
Wouldn't consider one for a tandem though, don't think it's beefy enough to be fair. A Tandem is going to put some massive stresses through any fork, and I'd be looking at something much more burly than a Maverick to take the strain for sure…
If you fancy one though, I have one I'm willing to part with for cash. It's been spare since I got another bike last year, JUST serviced (and not ridden since), and in overall not bad condition. Couple of bits of cable rub here and there etc, but overall not bad.