Jeff,
I've got a 97 900ss/sp with the same mods and a couple of more, as Joe B. On my bike it did make a very noticeable difference. Before installing the coils the bike was very hard to get started and took forever to get warmed up. It did not have a whole lot of punch either. After adding the coils the bike fired up instantly and I didn't have to fart around with the throttle waiting for the bike to warm up.
I also noticed a significant improvement in gas mileage.
I may have noticed the change more than Joe did because I installed the coils first then added the carbs, header system, etc.
If you have not done anything major to your bike yet, my guess is you will see a significant change with a set of new coils, wires , and plugs.
In my opinion for what it's worth, I am very pleased with the results.