i would imagine that the doors are great assuming you arent running anything too grandiose.
in the past, ive tried to run both 6.5" and 8" midbass speakers (recieving everything 150hz down and about 100 watts) and did not have great results. there was a lot of rattling and it was hard to seal the doors adaquatly. however....if you are just looking for a simple upgrade, the doors should provide a great and easy placment for the midrange speakers.
on another ntoe...if you are going for a more simplistic system, you can probably ignore all the suggestions for speakers ive made above. some of my favorite speakers in the price/availibility range you might be looking at are the cerwin-vega "vega" series and believe it or not, regular old pioneer cheep-o mids. again though, i stress that you listen to many speakers on your own to decide what YOU like.
