Has anyone here used a kit like this with good results. I remember putting a set of Progressive springs in my old 1100 Katana and it was well worth it.

http://www.ebay.com/itm/262394693829?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

Big subject here...Progressive Springs (the brand) are dual rate springs, not a true progressive spring.
Dual rate has 2 distinct rates, one of which compresses before the second rate takes over.
Hyperpro sells a truly progressively wound spring.
The spring rate increases incrementally for each unit of compression.
Hyperpro is very popular in Europe. I have used their kits and they work well for a cost conscious improvement.
I prefer Hyperpro to Progressive.
Single rate springs with dampening adjusted for the specific rider, by way of different valves and/or shocks, offer the most sophisticated improvement at the highest investment.
Things can improve even more when forks and rear shock are set up on a shock dyno.
BTW, I haven't thrown parts at my 14r as it has a reasonably good suspension from the factory.
Previous bikes, yes...

Thanks Hank. I went ahead and ordered the same kit stateside from EPM Performance Imports out of Jersey. Spent the weekend doing a valve adjustment/TB sync to get myself in fiddlin mode.