The gears can mean something for ET's if you improve your 60' time. That means that you must have absolute traction and that typically only comes with a bias ply tire like a Mickey Thompson ET.
I put in 3.33's in because I wanted to finish the quarter in 4th. I also had a little bog (with MT ET's)when launching under 4000, so I thought the 3.33's would help. Much to my surprise the difference was very noticeable and it is only 8 1/2% difference. In either the NA or NOS mode the 3.33's have made 4th gear a perfect street gear at highway speeds. I don't like the spacing up to 5th gear and personally feel that any higher gear is somewhat of a hindrance if it forces me to use 5th gear while racing whether on the street or strip.
Take a look at some of the posts by "pauls". Paul runs consistent 1.4 sec, 60' times (in the low 11's)with bolt-ons and 3.55's, of course with MT ET's. He even did a 1.3 sec at Beechbend. It is true, I saw the run.
As far as a Gen 1, it is harder to launch because of the suspension and in many cases more torque than a Gen 2.
Here are some interesting numbers. I measured three different rear tires, all with good rubber depth:
Mickey Thompson ET's: 26.6"
Pilots: 25.5
Kumho Ecsta's: 25.75
Because of the one inch plus difference the ET's effectively reduce the overall ratio by about 4%. In other words 3.07's become 2.95's, or 3.55's become 3.40's.