Just got another refurbished E300, this time travelling in economy from London to Paris.
Economy is definitely an improvement over the old trains. The tray is too small and the design is still very bland, but the seats are far more comfortable and I think there is more leg room than with the previous train. My biggest gripe with the new business seats (the head rest) is perfect for tall people in economy.
So, oddly enough, economy seats are now better than business seats on the Eurostar.