Without having seen it, there's a strong likelihood that you are correct. There are a large number of pilots who approach at too high an airspeed to begin with - well above Vref for the max gross weight when solo in the airplane. Adding speed to the approach for more weight just makes the problem worse.

OTOH, if you're used to flying alone or with one other person, the effect of being at gross on lift, load factor and CG can take getting getting used to. I had a very good student who had a little trouble with one of the 172s in the fleet because it was just a little nose-heavier than the others. Those small things do make a difference for newer pilots. In which case it's a 250 said - get out there and practice at the higher weight (and varying weights) until you're more comfortable with the need for minor variation of technique.