[lexlogan]

I did an extensive analysis of 4333 hands opposite a 15-17 notrump. There are four reasons not to use Stayman:

(1) Partner may also be 4333 (mirror shape.)
(2) They may double 2C for the lead.
(3) They may benefit from the info about opener's hand.
(4) The trump suit may divide badly.

No one reason is sufficient to avoid Stayman, and all but #1 apply to 4432 hands. (If partner has mirror 4432, notrump is probably wrong.) But #1 is sufficient to tip the balance against using Stayman; it occurs a whopping 33.6% when partner has four cards in your major. Meanwhile, partner is only about 33% to fit your major, and that along with reasons 2-4 argue against such nonsense as Stayman In Doubt.

On the other hand, these days players open notrump frequently with 5332 and 4225 hands, which reduces the odds of mirror shape and may well swing the balance back in favor of using Stayman on 4333 hands. If partner opens all 5332's in range, the odds that he will be 4333 when he matches your major drops to 24.4%. That still makes the odds of either 4333 or a bad break around 50%, but the 5-4 fit may play a lot better in the suit and throw in some 4225's and it may be worth it. Even 4333 opposite 4333 will sometimes play better in the suit.