Hell yeah you should go! I've made the trek to two Spring Flings. Nice swap parts, beautiful cars, nice weather, but....lots more to experience at the Nats.
I've been to almost every Nats since 1983 at Milan. Could've gone to the first in 81 at the Chrysler Proving Grounds in a buddy's 68 Charger but for some reason didn't. Also did not go the 2 years or so they moved it to Indy as a silent protest. National Trail is certainly not the best track in Ohio but at least there is racing on the grounds.
If I only go one day it's Saturday. It's about 2 hours away so that is usually a 6 AM to Midnight day for me. The bad thing is I spend virtually the whole day in the Swap and Car Corral area and typically don't see a whole lot of the racing and show cars. Two years ago I went twice. Took my van Friday to pick up a pair of AMD quarters for the 68. (saved shipping and got show prices) Then took the 68 down Saturday to be with my son and his Dakota R/T/ You need more than one day to go through the swaps, race car pits, show grounds on both sides of the track, etc.
The big name vendors are in the paved areas but the swap meet is off on the grass (or mud) be prepared for hot and humid weather, not dry like you TX guys are used to.
My favorite races are the Nostalgic S/S cars. I try to count them when they are in the staging lanes and typically there are over 40. I'm usually near the starting line standing just to the side under the bridge. Nothing like high compression big blocks and Hemis to shake your bones along with the fiberglass fenders. (except fuel cars)
It's not as awesome as it used to be, maybe the economy, but it's definitely worth seeing at least once.