I don't know about the North American lobster, but I was in the Australian lobster importing biz for 25 years....those guys had "regenerative" muscle, so a "G" size (20 to 24 ounce) tail was as tender and tasty as an "A" (5 to 6 ounce).
For personal consumption, I'd buy a biggie - much less expensive - and portion it out into the freezer.