Here in West Aussie there is a mix of roughly half and half ally and glass. Lots of ally in smaller dingies and runabouts and more glass in the bigger offshore rigs. Generally the only way to get a good ride in ally is with a deeper vee, then the thing gets too tippy at rest. A couple of ways to fix this is to build a deep vee hulled RIB like the AMF jet boats( I`ve been in a 40 footer with trip 300`s in 45knots plus weather on the south coast of Tasmania and it was very very nice) or borrow an idea from the Kiwis and put a flooding chamber in the keel. http://www.surtees.co.nz/boats/7-3-gamefishersportfisher.aspx . Pretty much the concensus here is glass is more comfortable, better ride, looks better etc where ally can get beaten up a bit, until a weld splits ( it has happened here and people have drowned) or someone loses a hook/swivel etc into the hull and electrolisis eats a hole in the boat.
All my boats have been glass apart from 14 foot tiller steered dingies. We`ve got a 24 foot glass c/c at the moment and are looking at buying a dingy for launching over rocky beaches into shallow dirty water soon. Some places you just cant take a glass boat.