For pure bench use the 1252a or b is better as its more accurate, but if you intend to take it outdoors quite a bit, the 1272a is more rugged.
Beyond basic measurements, both have specific features absent from each other, so list each out and see if some are more important to you. I frankly never use the added features.
I have both as they were given to me.
If I had to choose one, it would be the 1252a because I don't do field work professionally.