No problems with my Mirage Classic after 5 years. It's been a great kayak.
No problems with my Mirage Tandem. It's about the same age, but hasn't been used as much.
I just got a new Adventure. I'm anticipating the possibility of a rudder problem (new flip up rudder system), but am not about to let that keep me from the enjoyment of its unique features -- am confident that IF there is a problem, it'll get resolved.
In my opinion, this isn't a question of quality, but one of innovation. Hobie has always made a quality product. Yet, the nature of their continuing improvements puts elements of their product line at some higher risk of failure than those manufacturers who only produce "tried and true" merchandise. But look what they've achieved! My Adventure is miles ahead of the old Classic in virtually every aspect: the plastic used in the hull, fin material, rudder line, the Mirage drive, Rotomolding methodology, fittings, hatches, ergonomics, design, etc. etc. Even so, the Classic remains light years ahead of almost everything else on the market in terms of capability and versatility!
If you want a paddling kayak, there are lots of great choices on the market. But if you think Hobie kayaks offer some unique features that would enhance your enjoyment, my advise is, take the plunge -- I seriously doubt that you will regret it!