As part of SS, a 3D rebid by responder is also a multiple meaning bid. It shows either a slam try with the minors or a diamond-other major hand too strong or distributional for a jump rebid of 3N (which guarantees the other major, opener can correct). In response to ...
I don't know about you, but I hold far more weak hands than I do slam tries. As such, I would be loathe to lose crawling Stayman. Also, RS sounds FAR more complicated than SS, although It seems to do more.
I still think, as a less complicated alternative ...
I looked up SID but only found the 4333 meaning. My point was that SS shows 3 different hand types.
AS far as the merits of SS (or any convention) are concerned, aren't the criteria involved:
1-does it work
2-does it gain more than it loses
Once you use Stayman, you tell them about your major. If partner has the other major he jumps to 3N and you correct. The only extra info they get with SS is whether or not you hold a 5-card major, which I think is more useful to us.
With a 4333 game hand you no longer have to decide to use Stayman or jump to 3N. Using SS, bid 2C and if partner bids your major, say 2S, bid 3C. Partner will rebid a 5-card major or 3 of the other major with 4-4. Over either bid, partner ...
Sorry, forgot to answer your question. Over 3D, responder bids 3 of the other major. If opener bids the other major you have a fit and can try for slam. If opener rebids his major (showing 5), responder relays (over 2S-3S, 3N must be a slam with hearts and clubs ...
3C is now multi purpose: game+ with clubs and the other major; square game force with a major; game force looking for a 5-3 fit.
Yesterday, we reached a slam with an opening 1H with partner holding a 1N hand with 5 hearts, while other expert pairs started with 1N ...