Waldorf  Microwaves are top wavetable synthetizers, they are the direct descendents of the awesome PPG WAVE.

Analizing the two models (assuming that the XT is an enhanced version of the 2, but it sounds the same) the most important difference is the fact that the Microwave 1 is a hybrid synth with digital oscillators with VCF and VCA (so an analog 24dB lowpass filter for each voice and a vca) while the Microwave 2 is a fully digital DSP synth.

The differences are evident, the microwave 1 has a more organic and warm sound, sound heavier in the mix and is darker, the microwave 2 is more versatile as the synth has multimode filters, a cleaner sound and a lot more functions, but it sounds colder.
One thing to notice is the envelope clicking.
Both the 1 & 2 have env clicking, but while the 2 can be prevented from clicking with a well programmed env curve, on the mw1 the attack clicks, so this noisy attack cannot be avoided.
here is a demo comparison from Retrosound youtube channel: