I had one for 11 years on my last boat. The only problem I had was with the nylon ball bearings on the lower drum. They are prone to UV light and mine disintegrated after 5 years use. I had them replaced with stainless steel ones. Apart from that it's given years of trouble free service.
Mine is 15 years old - it was on the boat when I bought it. It works very well & I've had little trouble with it, namely:
A split foil where water had frozen in it.
Friction on the top bearing (cured by a replacement with a more recent bearing)
A locking grub screw coming undone linking two of the foil sections together.
I would add that the first was a result of poor maintenance by the previous owner and the last of poor maintenance by me.
The company are very helpful and are willing to spend time discussing problems over the 'phone. Their service is very quick and very good. I had the whole thing overhauled last year, including a new forestay, for a very reasonable price.
One of the best companies you do do business with!
My Rotostay II furling gear was fitted to the boat in about 1990 by her last owner. Last year a met them at the Southampton Boat Show and related a problem with the eye which feeds the reefing line.
Rotostay's response was to send a new eye, modified as I requested - they even included a tube of locktite and a new alen key just in case.
A few weeks ago the bearings (Delrin) finally failed in the assembly which slides up and down the foil. I called at noon on a Friday and a complete new set were delivered in Saturdays post. Total cost was £19.00 (+ the price of one first class stamp). I was advised by their MD and felt they really cared.
Hats off to companies who support their products after so many years AND who still give personal service.