I originally had a Rib Raider fitted which I replaced with a Metz which I replaced with a Pacific from Mr Channel as above, all in the space of two years and 70 hours use.
I have not tried the Pac yet as I only recently fitted it, but it is well made. Only thing I would say is check how long your coax needs to be as I had to join mine to the old antenna coax in a damp space under the seat which is far from ideal. I think the coax is 5m long but that is not long enough to reach the console through under-deck trunking on a 5.8m RIB. As it is a captive cable and sealed into the antenna mount you have no choice but to cut the supplied plug off and join it if it won't reach - mine was about 1m short. However it is good quality and easily removable leaving about a 1" projection from the A frame which is supplied with a rain cap to keep the water out when the antenna is off.
Previously the Metz I had performed well except that the stainless mast kept coming loose (it's held in to the antenna base with a compression fitting and an olive, and the mast kept working its way out of the olive even when tightened very tight). When I eventually bit the bullet and tightened it enough to retain it, something turned inside the base and though it looked OK it never worked properly after that. Great antenna performance ruined by a poor mast retention design which isn't up to the banging around it gets on a powerboat. Salty John who I bought it from were very good to deal with as well - first class service as is Channel Ribs.
People knock them but the old RIB Raider I had worked well... until it fell off. Seems to be a feature of boat aerials - if you have a 4x4 you can buy an antenna for £15 that lasts for 10 years but stopping things falling off boats seems to be hard work