The interior of the 987 is beautiful compared to a 986. The exterior though...I dont know. The 987 has been "pancaked" a bit. Its lost some of the beautiful curves the 986 has.
Try not to compare the performance numbers of these cars. Instead compare how they feel to you. Many say the base 987 has a pretty sweet feel to it.
The 986 has already depreciated and has flattened out. Once the cars are in the very low $20,000 range they stay there. The 987 will come down $15,000 in a few years...lost money.
If only they built the 987 interior into the 986 body...OMG! HEAVEN!