As others have noted on rec.games.bridge, everyone is
- very good at announcing their opening 2-bids
- good at announcing "hearts" and "spades" as transfers over 1NT
- fair at announcing stayman
- abysmal at announcing the 1NT range
A few pairs also tried to announce transfers over 1NT overcalls - assuming announcements survive then I expect this may be one of the first revisions.
The changes to the alerting procedures all seemed positive and we had no problems. A number of us started to alert bids above 3NT (hand reaching the bidding box but then rapidly withdrawn as if seeing a snake inside it) and the new rule, of not alerting above this level, is a massive leap forward and seemed universally popular. We, and others, delighted in alerting conventional doubles and passes above 3NT just to show we knew what we were doing - if only we could remember whether it was 'at 3NT' or 'above 3NT' where the new rule came in :)
Having played with announcements in the USA, the scheme that the EBU has adopted is similar but less consistent. Aside from extending announcements of transfers to all natural NT openings and overcalls, the rise in the number of Short Club systems means that the USA announcement of "may be short" would significantly reduce alerts and explanations.
Personally I am not convinced of the value of announcements. However (when in England) I played exclusively tournaments and almost no pairs events so I do not provide a representative opinion. Now in Scotland, I find that everyone announces their notrump range and weak 2-bids at the start of a round (even in clubs), so the value of announcements would be significantly diminished.
The new alerting procedures are a definite improvement. In particular no alerts above 3NT. Personally I would also recommend that no doubles are alerted, but understand many may feel that this would be a step too far.