The differences are obviously only confined to the ground, trying to leave it and then getting back on it in an orderly fashion. The theoretical additional forces (P factor, etc) in the 65-150hp range that I have flown seem to be almost non-existant really. Perhaps in a Harvard or a Corsair with 13' prop blades, things would be different. The crosswind limits are lower, certainly I feel near my limit with a mere 8 knots in a PA17, whereas 20kts in a tri-cycles is obviously not undemanding, but doesn't seem to be an issue. T/D landing roll, can be interesting. Our group asks that you get checked out on tarmac runways specifically. Not sure if this is over zelous or sensible. I'm quite happy to go with the flow on that. I've seen some comments that relate the need to use the rudder to taildraggers, from memory, the PA18 does seem to have a little more adverse yaw than a PA28. The PA17 with its little wings doesn't exhibit much at all.
All in all, for a new student I would summise that the tri-gear is better because it permits some rough handling and mistakes (particuarly on landing) without being soul destroying, aricraft damaging or downright scary, I don't see any advantage to making things difficult at the ab-initio stage. Also the tri-gear probably permits perfectly safe operations in a wider ranger of wind conditions, which is good for any student. Everything else: circuit, climb, descend, unusual attitudes, navigation, S&L, PFL, etc, etc is exactly the same.
If difficulty is seen as the best ab-initio training aid, then why not start with an Extra 300 and then progress to a PA28 once mastered
