Ah, yes - another believer!
Perhaps I have low expectations but I have not yet flown the J3 and been in the slightest bit bored with 65HP or 73MPH. If the HP is a problem it is perfectly possible to upgrade to a larger motor(up to 100 HP, but 85 apparently the best all-rounder) but you lose the charm and originality..
From 1946 on the J3s had metal spars, but if you want a fairly original L4 it will have wooden ones. ADs as Kingy says are not a problem - most relate to the 40s and 50s - but as he says check the struts (almost£2k for sealed units with larger forks -well worth it quite apart frm the lack of repeat checks) and the spar strut attach fitting inspection AD (hole cut in LE wrap to inspect forward facing fitting). Check for corrosion on the lower fuselage tubes (not only at the back!). Ensure the wing/fuselage/engine mount and tailplane are all square to each other! In flight, carefully check the trim operates without slipping. It's a very simple machine and easy to work on (except the trim system which can be trying) so that adds to the enjoyment! No question, therefore find a Permit aircraft
On the minus side cramped forward seat, inability to reach the instruments from back seat, 20lb baggage compartment and a crap cabin heater. Standard 12 USG tank limits the range especially when the wind is blowing so accept that you'll make plenty of fuel stops! Again, perfectly possible to find machines with wing tanks, or you can fit one yourself. I use Mogas at home and have had absolutely no trouble (£12 or £13 an hour!!) The Brakes are, well, J3 brakes and here I disagree with Kingy - I think that they are perfectly adequate (a lot of nose overs are on Cubs with disc conversions) and are fine for strip flying and absolutely essential if you want to operate in goodly x-winds or land with any downwind component so it's best to keep 'em serviced. Inner tubes and tyres are hellish expensive, too.
STOL is a given - absolutely no trouble with 300m at all up weight, nil wind and Summer temps. A lot less than that if conditions are right. One up and light you can really have some fun!! Ground run are v. short during TO and Landing but angle of climb is poor. Sorry. But, as I say, if it's windy you've got yourself a poor man's helicopter!
Anyway when it comes down to it, bimbling along at 70MPH, doors open at less than 1000' on a summer's day is heavenly.
Especially, when nonradio...