As a serial -4 owner, I'd have to reluctantly advise avoiding the -4, if you expect any extensive cross country work or 2-up acro. The back seat is pretty tight, 32 gallons means range is somewhat limited, baggage space is limited, CG can quickly become an issue, and gross weight can become a factor, as well. My -4 was/is pretty light (930 & 910 lbs) and so is my spouse, but with her in the back, I'm still limited to around 50 lbs baggage. Acro gross is around 1350, so with 180 lbs of fuel, there's not much capacity left for a passenger.
But... If 2 seat acro and 2 seat cross country aren't factors, it would be hard to find a better flying a/c.
Charlie