I wasnt thinking when I replied, but with adjustable needles (ala everywhere else but the US it seems) you'll stand a fair bit better chance. I will warn you, I HAVE adjustable spec MiC needles, and it was still not working the way i liked. There is just not enough taper, adjustable or not.
And, just a quick word on your "tuning theory and practice" Theory and practice are often vastly different from each other when applied in real world scenarios. I followed, to the letter, the Factory Pro tuning guide while trying to hand jet my 1100E. What I ended up finding, and what you may end up finding yourself, is that, because you're tuning from the top down (main first, as it meters EVERYTHING in a BS series CV carb, from the Pilot up..) You may run into a situation where you get VERY VERY close to having the bike run the way you want it, but to do so, you'll end up with a MASSIVE main jet. This will, in fact, contrary to what some of those tuning guides will tell you, effect EVERY circuit in the carb. So, you could have a bike that runs great through the mids to WOT, but reeks of gasoline at idle, idles like crap and gets abysmal fuel economy (in reality, MOST of your riding time is centered around the pilot, pilot needle transition, and just into the needle... maintenance throttle, or off idle cruising throttle could be massively effected..) . Or it could run great off idle, and from 1/2 throttle up to WOT but fall on its face on the pilot/needle transition, or many different combinations from there..
What you're paying for in the purchase of a DJ kit, a Factory Pro kit, or any variation on such, is the R&D in the design of the NEEDLE itself. The jets are simply MiC jets, with a different measurement scheme employed to make them that companies product. (For instance, one may use the actual diameter of the jet as the determining factor in the "size", another may use the actual flow rate, some other still may just call it whatever...)
The Needles employed in these kits were specifically designed to deliver the necessary amount of fuel through the mid-range, based on the given main jet size, to allow the bike to run as it should after an intake/exhaust change has been implemented. I dont think anyone here is attempting to put you down, change your mind, or anything of the like. And Yes, Steve is a good guy, and we've had our debates about reasoning behind adding pod filters and or exhaust systems..
Oh, and, for the record, The biggest gain on switching to a 4-1/4-2-1 on a GS is WEIGHT SAVINGS.. I could go into another rant about pipe diameters, flow rates, etc.. but we'll save that for another day
