Absolutely, positively, yes.
My iP4 is now so much better under 4.3.3 JB then anything I've ever owned.
So much I need that's not (yet) in iOS5 including the masterful SBSettings (and life saving SBSchedule) that I use dozens of times a day as I move from home to the motorcycle to the office, etc. One touch to turn on/off WiFi, Push, 3G, adjust brightness and volume, etc. is PRICELESS!
I theme the heck out of it too. Love being able to adjust lock screen and springboard to display useful info on the fly via widgets and lockinfo tweaks.
Infinite size folders, folder icons instead of thumbnails, tetherme, and on and on.
Also could not live without Activator, AnyRing, Calendar Colors, Weather Icon, Clock Icon, and voice activation (though that might be in iOS5).
As keen as I am to do my annual hardware refresh, I'll not touch iP5 or iOS5 unless and until an untethered JB exists for both.