Have to disagree with pretty much every comment here.
Honestly, I think its healthier to not buy things based on how you think others perceive them, BUT... NO ONE looks at the 308 and says "nice old Magnum PI mobile" and then looks at the NSX and is somehow awed. I mean come on. I love the NSX, but 99% of the population have no clue what the hell it is. MOST people recognize the 308 as a classic Ferrari. This argument is silly.
As for a Civic Si beating it. Who cares? Thats another ridiculous argument. A Civic Si can "beat" a Jaguar XKE also. A new $25k WRX comes brand new with a warranty and can annihilate any NSX that hasnt had $20k in mods in *everything* from a technical standpoint, so why arent we all just driving WRXs?
The 308 is a classic car. The NSX is also, but the 308 is even older.
The question of "should I..." is HUGELY subjective on a classic car. Anyone who immediately jumps to measuring *any* classic against current cars is, IMO, kidding themselves and destined for disappointment (that includes the NSX). Its why you see people on this very forum so desperate to figure out how to benchmark the NSX against a new Z06 (sort of laughable)
You buy a classic because you love the experience of *that car*. In exchange, you have to accept it for what it is.
If you get in a 308 and think "oh crap, this feels OLD!" and you look at it and think "oh man, this didnt age well!" or you drive it and say 'woah... my CIVIC is faster" Well then the 308 is NOT FOR YOU.
I can tell you now that many of my friends think Im insane for owning a CTSC NSX when for the same money I could own an endless list of cars that are *far* quicker, more modern, and handle better. But to me, the NSX puts a smile on my face like no other car does (with maybe some exceptions
)
To the OP, THAT is the answer to your question. If the 308 *speaks* to you more than the NSX, thats what you buy. If the 308 just feels old and dated (and you NEED to be honest here), but you are looking to try to gain some sort of artificial "I have a FERRARI status" (and MANY do this also with the roughest, cheapest, NSXs), then you are making the wrong move.