I read that site before I installed my pod filters, but I went ahead and did it anyways. I think the problems people have with the pods is that they try and change too many things at once, and that they're using a Dynojet kit.
Dynojet kits are a huge ripoff. For the most part, they don't work at all, and it's a whole lot easier to use your OEM parts, with a few modifications, to get the bike to run correctly.
I installed two EMGO pod filters on my 1990 EX500. I didn't change the exhaust, and I didn't change anything in the carbs. Took it for a ride, and noticed that it pulled great in the upper rpm range, but midrange and low end hesitated. I pulled the caps and shimmed the stock needles with a .020" shim, and that fixed it. Bike runs GREAT at all rpms, and I can lug the engine in 6th from 20 mph on up to 75 (ran out of road). Going to ride the bike a bit and see if my plugs show I'm lean or not, only then will I consider a new main jet.
The problem with Dynojet kits is that they change EVERYTHING, and do it all at once. Drilling your slides to make them rise and fall faster, new needles that have a different taper than OEM, and that are at a different position than OEM, stiffer slide springs, and different main and pilot jets. I guarantee if you follow the instructions and do all these mods at once, the bike is going to run like absolute hell, and you're going to spend every waking minute trying to figure out why.
You CAN get good results just by shimming needles (IF necessary) and replacing jets. There's no need for different needle tapers (which usually way over-richen the midrange) or modifying the rate at which your slides open (chances are Kawasaki engineers, with years of experience in designing carbureators, know a lot more than the dynojet guys).
Heck, even if you do go with the dynojet kit, just go one mod at a time (just needles, or just jets, or whatnot) and find out how that makes the bike run, whether it's a good change or a bad, and how to fix the problem or whether to keep the OEM part in that case.
Anyhow, my EX is running great with pods, and I think the intake roar is tits! I suck small children off of sidewalks as I ride by, and I have to keep yanking squirrels off my intake. MWA-HAHAHAHA!