Hey lewisallen - you'll get lots of good advice here (often differing...) but the general consensus is that 280/300's can be a bit of handful for a first time bike - best advice I've heard recently is that whatever you buy now, you'll be looking to upgrade as you get the hang of things so buying a first bike that's popular from a resale/trade in perspective has merits - That would point to a 250.
Welcome and have fun
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