thats what advice i was offered as well in the d5, interestingly looking at my old invoices from ocuk that was the same pump i used a few years back as well so the d5 must be doing something correctD5 is probably the best.
The DDC is not a bad pump though and works well in small cases due to its size.
My rads are external as well and sit in a filtered box on a windowsill so that they get cooler outside air through them. Awesome temps in the winter!! Pumps and reservoir are also external.
how long do pumps like these generally last if the loop is well maintained?
I prefer ddc's now after using D5's for years. The new pwm ddcs let the pump run at 1300rpm making it inaudible.
Still the D5 vario IMO.
A lot of manufacturers are trying to push PWM pumps as a thing these days, it's still not as good/simple though.