That's up to you. I didn't find the need.

Just the opposite, Not a Cub fan (White Sox

) and the '5' was a stellar upgrade for
me from the '4s'---which my wife loves. In fact, I've found each iteration to be an excellent update...and my wife enjoys the hand me downs...which works out well now that AT&T has gone to the two year update schedule. LTE alone, much faster, display, the new connector is fantastic...it was an easy choice for me and speed-wise (I do a LOT of surfing and use the iPhone for tethering often) with the LTE update, the increase in speed and graphics while secondary is a definite and obvious/evident performance increase in everyday usage. I love the '5' and am excited about this fall's release. I'll buy it...and at dinner the other night, I showed my wife several different examples of her 4s side by side with the 5 the 'differences'. Loading a website, opening the app store, downloading a song from iTunes, and finally we ran the SpeedTest app for real numbers. She was impressed (and typically isn't in technology)...and agreed 'on the spot' to take my 'hand me down'
That said, we do agree on the fact the OP should now wait out the 5s/6 or whatever happens this fall. The last couple of iterations of iPhones have had marked increase in performance---in most cases @ least a 100% increase in CPU and GPU performance.
buying a iphone 4s made no sense, you should have waited for the 5 in my opinion, it's an actual upgrade.
I'll second that 'laugh' of Viper's. The 4s was and IS a huge upgrade from the '4'. Anyone that's owned both knows the truth. The performance, speed, camera....all the way around, while it didn't change from the outside, the guts were completely re-worked and you'll see just HOW big an update it was when iOS7 hits.
OP---No question. The 4s is an excellent phone and while lacking LTE, you've waited this long, another 60-90 days ought not kill ya! Wait it out. You should still be able to sell of your 4s for nearly what you'll pay for the new '5s' or '6' (subsidized) or iPhone X----whatever the name of the new one is. Good Luck
J