Wasn't plate but I did go from aluminium to glass. Both have good and bad points and a lot will depend on what type of boating you do, what hull you pick and how it's looked after. Biggest thing for me with alloy was that I was sick and tired of chasing corrosion issues. I had owned the boat 20 years and am now of the opinion (wait for the howls of disapproval to this statement) that alloy hulls have a shelf life. This is based on working in the marine industry and long time alloy ownership. Not an issue if you buy new or newish, keep it ten years and move it on. Keep it 20 years though and unless you have been meticulous with your cleaning and upkeep, corrosion starts popping up. We are currently refitting an aluminium workboat at work that is at around the 20 year old mark. The level of corrosion in some areas is astounding. In some areas it's expected but in some areas you look at it, scratch your head and ask why? I look at it and think to myself just how good some of the sealed bilge plate boats going to be in the same time frame if they have had a bit of salt get into the bilges through a bung seal that then couldn't be washed away. In some areas of the raw water system on this boat the corrosion has eaten through 10mm plate. The biggest hassle with old alloy is welding it. None of the guys that I know love welding old aluminium and they tell me repair is never as strong as the original hull.
Glass obviously requires care and attention as well but there are plenty of old glass hulls that have been successfully rebuilt and are going strong 50 or more years on. You do tend to need to be a bit more careful around ramps and pebbly type beaches.
Ride is generally regarded as better with glass but that is purely a function of hull design and weight. Build a tin rig with the same deadrise and weight as a glass rig and the ride will be similar. Some alloy hulls are significantly noisier than glass too.