Argee, here's my thoughts. Yep, I say, performance-wise the T-Bird WOULD be a definite "upgrade". Looks-wise, a slight "downgrade". Handling-wise, a VERY slight "downgrade".
And so, I guess it all pretty much depends upon your priorities here, and IF your MAIN priority would be to purchase a bike for longer distance commuting and with the extra power to MORE leisurely criuse along at superhighway speeds, THEN I can see why you're considerin' this trade-in.