I never said that ALL of the dc pumps fail in 8 months, and I am not speaking from experience either...just what I have read recently. I will further elaborate on what I have found in my recent research, and I am in no way attempting to bash or discredit these pumps I am just repeating what I found online as I am in the market for a new return pump.
My 8 year old quiet one has been periodically letting out a loud hum lately, compared to its usual dead silent operation which makes me think it is going out so I have started looking around for a new return pump. In my research I stumbled on recommendations for waveline dc return pumps. Looking at the flowrate, power consumption, available head pressure, and power consumption coupled with price these pumps seem to be a no brainer and a winner in every department. Further research lead me to jaebo, speed wave, waveline, diablo, and royal exclusive dc return pumps. I later discovered that the waveline, speedwave, diablo, and jaebo are all manufactured in the same plant in china and are basically the same pumps with minor differences. I found several threads where the people who got them were exclaiming how great they operate which got me more excited. However, further reading into the same threads I found the same people who just got them and were exclaiming how great they were had them fail in six to eight months. This seemed to be a very common issue, and I found myself a little disheartened. It seems it is common for them to fail in that time frame, and that getting them replaced through warranty is difficult. I even seen speculation that premium aquatics quit carrying a couple because of to many failures (but this is speculation).
But there is one that is warrantied through coral vue (waveline I think) that people are able to get replaced extremely easily. I think it is the most expensive, but comes with a longer warranty that is honored right here in US...so the extra money might be worth it. I still have not purchased or made a decision on my return pump, which is why I am participating in this thread...right now I am leaning towards a magdrive or sicce or another quietone because they are tried and true workhorses that require literally no maintenance. Also been looking into laguna and fluval pumps, but I still am considering giving one of the dc pumps a try...the price vs flow and power savings seems so awesome, just lots of reports of failures. They are relatively new to the salt water aquarium industry and you can see design flaws being worked out with each new release, there's no doubt in my mind that in ten years mostly everybody will most likely be running dc return pumps. Especially after a couple start getting manufactured here in the US with higher QC and build standards.