I bought a jager because I read about people having them for 20 plus years on here... guess they don't make em the same anymore.I like the design its solid, simple, basic, and dynamic(because you can calibrate it). At the end of the day it has to work though and not shock your fish. A 50 percent failure rate is not acceptable to me. I hope I have a better experience with these new heaters.
I bought (6) 300W Jagers a week ago and they are definitely not the same quality that they used to be. I remember the older models feeling very solid...these new one's appear to be made out of thinner glass (although still thicker than most other heaters out there) and the plastic control knobs also feel cheaper. As others have mentioned, I don't think there is a clear cut "best" heater out there right now, but I think Eheim is still better than most.
This brings up a good point. We're probably lucky the stealth pro was a marineland product and not eheim. Eheim probably still have gotten back to anyone on the heater issue from what you hear about their customer service. Based on customer service everyone should probably buy from aqueon and marineland.
Eheim customer service is pretty slow, but I had a 2073 (Pro 3 G90) leak on me and they sent me a new pump head no questions asked. Granted, it took them several weeks to even acknowledge my initial e-mail, but they stood behind their product.