I haven't seen the need for a downhaul on the DS (the way I sail it). When not single handing there's always crew to send onto the foredeck
Seriously, haven't missed a downhaul. On the other boat, the furler came pre-installed. Easier to rig on a trailer than I had anticipated, but in operation has jammed occasionally, usually on unfurling. Esp. annoying as with that boat, unless crewed, it's impossible to go forward without flipping the boat (one eager crew tried this at the dock and when I returned from the parking lot with the trailer found her bobbing like a cork...
Oh, the memorable moments!)
For the DS, if I ever get the courage (and spare budget) to follow K.C.'s lead and add a UPS, that would go on a furler. In which case I might want a DH on the jib.