Hey M.Rad I no longer own the other 2 bikes but I would be glad to give my impressions and reasons for getting the ZX11
I owned a 97 Blackbird which I LOVED and regret selling. It was pretty modified with custom cnc'd risers w LSL bars, a 2012 entire Busa front endw Busa fender w the radial brakes, Penske 8983 double adjustable rear shock, Factory ignition advancer, Dyna Coils, Yosh 4-1, K&N filter and Stage 2 jet kit. Numerous additional mods included delinked brake system, Carbon fibre inner fairing panels, Pazzo shorties w custom brake master, HEL stainless steel custom brake line kit, Gilles adjustable rear sets, a custom rear brake bracket to allow a Brembo rear brake conversion kit and Samco silicone rad hose kit and upgraded mosfet kit. Corbin seat and a custom windshield. The XX was fast enough, I think a tad quicker than the ZX11. I liked the gearbox, it was solid. My ZX is pretty much stock. Fit and finish goes to the Honda hands down, Smoothness goes to the Honda and its stock brakes were better than the stock ZX, the linked were okay but I delinked to go separate. I feel the XX looks better in stock form as well but thats subjective. I sold XX at 110,000km , my buddies 02 looked and rode mint at 210,000 and he did his first timing chain at 190,000. The XX is a really really good bike and I would buy another at the right price with all the right mods done in advance, BUT I would want a 97 so it could qualify for collector/vintage plates sooner.
My sole reason I sold the ZX14 was I found I have not been riding as much as I used to and the 08 ZX14 was farkled right out with the front AK-20 Axxion Cartridge Kit Ohlins rear suspension, dual fan rad mod, Sargent seat, PC, Yosh slip ons, risers, full Givi luggage, Yosh undertail , LED's , heated grips/vest and radar plug in and custom screen. The ZX14 is really really good and after getting off the ZX11 before I sold the 14 and then riding it back to back it is like night and day w FI. The one drawback of the ZX14 for me was the disgusting amount of heat the engine throws out in city driving, when you get stuck in traffic it is horrible. It is another level well past the XX and ZX11, the extra displacement throws off alot of heat. The bike imho handled amazingly well , comfort with my mods was excellent and smoothness was great. The ZX11 to date I am really enjoying it and cant wait until Dec 2020 when it qualifies for collector plate and real cheap insurance. I can then complete some of the mods I am collecting and I feel the bike will be all I need, fast, comfortable and better handling than it currently is. Nothing wrong with the ZX11 at all, I am happy I bought it , i did find the XX to feel smaller. I owned the XX and ZX14 together for a short period then sold the XX and had the ZX14 along with the ZX11 for a short period then sold it. The ZX14 is just so strong it wild, I don't require that type of power any more as I get older and you just cant use it on the streets and still be responsible but when you do find the right stretch of road as it is with all three of these bikes , wow what fun:)
My mods for the ZX are
Oxford heated grips
Givi Touring Screen & Lockhard Philips screen
LSL Conversion bar kit 2 lines for brakes
Hindle 4-1 new or ZZR 1200 header w Delkevic 13" tri ovals
Factory Pro jet kit
Factory Ignition advancer
Dyna DC1-2 coils
It's amazing the number of customization you've done to your bikes. It should be really a joy having at your disposal all that funny pieces, here in my country you hardly find any simple OEM part...
Please post some pictures of your heavily modified XX.