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I know some would be bored by this question but as a consequence of A) being something of a perfectionist and B) still not having enough experience with type, I just can't pick up a typeface from one of the mentioned foundries/vendors and not think about whether the others' versions of the same would be better.
There has to be at least a hundred classical typefaces being offered by all three if not even more vendors. Sometimes it should really be the same digitalization because they share(d) licenses, LT is owned by MT etc. but often there are differences between the designs. Do you have a general rule of thumb you can apply here when choosing? E.g. Monotype has older versions and Adobe or LT had technically improved them or LT is more like ___ while Adobe is more ___? Or like one pays more atention to kerning, the other has the original designs... these questions drive me crazy and I just can't spend half my working time comparing the cuts everytime I need a new typeface ;-)