Every Joe blow has a BMW, i believe that handling wise there is little to no comparisson i would most def go with the boxster we have a 1999 and it is just alot of fun drop the top and everyone is looking. Might not be the quickest thing in the world but its alot of fun. If you buy the porsche iwill give you my personal guarantee that you will not regreat your decision. That is just my opinion my dad has the boxster and his business partner has the 330 and in a race the boxster may have the lesser of the horse power but it is a close race due to power to weight ratio. I can also ensure you that there is always a bigger grin on my dads face than his partners knowing he is driving a porsche. after all there is no substitute.

 

I also agree and BMW Parts is durable and reliable.

 

I think you will feel more "Driving a convention car" in a 330, it has rear seats, engine is in the front, get a trunk in the back.....
One the other hand, the Boxster engine is right behind you, you can hear the engine noise all the time. either you like it or hated it. Sometime, I wish itis not as loud all the time. Boxster is a more fun to drive, the two storages is pretty good, I even can stop at Costco all the time. Boxster's handling is one of the best, cornering is super. Porsche will be more a head turner, more people look at the Porsche than the BWM, this is just my 2 cents.
My Boxster S is my primary car, but my wife and a 4 door Benz, so it have when I need to room to do more shopping.
I am Porsche guy, that why I go for the Boxster.
It is fun to drive.

Life is short, drive nice car.