Of course, all amps that work at 2ohm load have bigger transformer to generate higher rail, higher voltage rail caps and maybe higher voltage output mosfet to put out the same (or close) power of the 1ohm amp, that have smaller transformer, lower rail caps and rail themselves and lower voltage output mosfet (not necessarily) but probably higher current capability due to the very low impedance use.
"Smaller transformer"? Do you mean physically smaller?
I wouldn't expect there to be much of a difference in size. The ratio of windings will be lower but I'd expect them to use more copper on the secondary of the lower impedance transformer to maintain the same standards (circular mils per amp) for the windings.
I wouldn't expect there to be much of a difference in size. The ratio of windings will be lower but I'd expect them to use more copper on the secondary of the lower impedance transformer to maintain the same standards (circular mils per amp) for the windings.