Found this in another forum:
MR2 Pro -
lower repair costs
better fuel economy
cheaper tires
lower initial cost to buy
more reliable
People sometimes mistake it for a Porsche (is this a pro or a con?)
MR2 Con -
Noisy harsh motor
NO TRUNK SPACE
Poor handling compared to Boxster - I never found the MR2 as tossable as its low weight suggests and I had good tires on the thing.
Low power
Boxster Pro -
It's a Porsche
Power
Handling - very big difference
Interior Room
Power top
2 trunks - both are bigger than the MR2- the Box has 3 times the trunk space of the MR2
Quality feel
The top down experience is better than the MR2. The wind ruffles your hair just the right amount. The engine noises top down are very, very nice.
Boxster Con -
purchase price
repair costs - expect to pay 4 times more in maintenance than the MR2
worse fuel economy
premium fuel required