I've had several fibreglass antennas of varying lengths over the years with no trouble at all. At £40 or so who cares if it only lasts a couple of years anyway?
I've got a 2.4m Comrod on top of my a-frame at the mo, lets me chat to Solent CG from Alderney (60+nm) like I was sat in the ops room
I love Icoms as well but if you've got a Garmin plotter then buy a Garmin 200 vhf, it'll plug straight in the back of the plotter (N2k) and give you all kinds of extra functions i.e. plotting DSC alerts on the map etc. It's a perfectly good radio by itself anyway