only serious design flaw of the PA28 is lack of 'both' position on the selector.
...and of course the selector is in a really hard to see place, next to your left knee.
Try to keep the fuel level in both wings more or less level, by changing tanks every half hour or so. Different people have different methods they use - find one that works for you. More than a few gallons difference left/right is noticeable in lateral trim. Technically, you could use rudder trim to correct, but most people recommend not to touch the rudder trim at all. I find it's not very effective anyway.
Another design flaw I find is the carb heat control knob. Right location, but very flimsy for a control you need to touch at least twice every circuit.
Oh, and what I find in the PA-28s in our club: Piper has offered too many options in the past. All our aircraft have a different history and as a result all Warriors have a different panel layout. Yes, the basic T is in the same location, as is the RPM. But we have four or five different locations for the "avionics master" switch, if present at all. Some have clocks, some don't (and one has the clock wired to the main bus instead of direct on the battery), some have an autopilot, some have GPS (3 different types altogether), there's at least three different types of transponders, two different types of audio selector panels and so forth. So every time you step into another one, you spend a minute or two looking for where is what. Not very confidence-inspiring to your passengers. I don't know yet about Cessnas, but at least Robins and Diamonds have the same knobs/instruments/avionics in the same location across different aircraft. (Granted, most of those were bought new from the factory by our club.)