The A-110-2 Basic Oscillator is a great-sounding oscillator, with interesting additions to the A-110-1 Standard Oscillator. While the -1 has a 5-position switch for octave, the -2 has only 3 positions. The -2 also sacrifices the sine output from the -1.
While the -1 has linear FM (i.e. a second 1V/Oct CV input with an attenuator), the -2 also has exponential FM. And while the -1 has a sync input, the -2 has both hard and soft sync inputs. The -2 has only one input for pulse width - but that seems like a reasonable sacrifice for the other features.
I find that the A-110-2 doesn't track as well as the A-110-1 in high ranges, and the sound is a bit "grittier" than the A-110-1. I actually like the square wave output of the -2 better than that of the -1, and since I have two of each, I tend to use them together to add texture to patches.
All in all, for the small price savings and the 2HP difference in width, I would tend to buy the -1 first - but I would buy a -2 to go with it, too.