With the above hand and equal or unfavorable vulnerability, (all xs are 7 or lower), I would not be inclined to open 1NT even with 15 hcp, opting instead for one club. The reasons are 1) short major suits, and 2) a lack of "intermediate" values (Ts, 9s, 8s), leading to a possible situation of "aces and spaces."
I would open 1NT if the above hand were upgraded to:
Here, I have my "statistical expectation" of one T, one 9, and one 8, well placed, in addition to four face cards. I would value the second hand as at least one point, and maybe half a trick better than the first. Was I right to downgrade the first hand to 14?
I would open 1NT with this, after upgrading the 14 points to 15. My reasons are 1) The fifth card in my strong suit might be worth an extra trick. 2) The KQJ sequence deserves a premium, especially when followed by the 9 (never mind the T). 3) The Ax doubleton is a sure and not a shaky stopper like Kx or worse, Qx. Change the Q of spades to the Q of clubs and I would not open 1NT with 14 because of the broken spade sequence and the flat 4-3-3-3 distribution.
Are these reasonable ideas?