[Stephen Tu]

GIB holds ♠3♥KT♦AKT5♣KT7543
uncontested, auction goes:
1♣ - 1♠;
2♣ - 2♦;
4♦ - ?

Problems:
1. 2♦ is defined as 4+ spades, 4+ diamonds. I don't think it should be guaranteeing 4+ diamonds. What does responder do with a forcing hand with spades + clubs for example, 5xx4/4xx4, or various 5(332) hands for example? I think 2♦ here should be 4+ spades, 3- hearts, 10+ pts, but otherwise unspecified.
2. Because of (1), I don't think opener should be allowed to bid anything beyond 3nt, personally. Raising diamonds fine, but 3♦ should be enough? I think priorities should be spade support, heart stopper (2nt), raise diamonds, rebid 3c as default.
3. Responder wanted to take a preference back to 5♣ to play, having temporized with a 5332 hand. But 5♣ is defined as a cue bid for slam with diamonds agreed. One should be able to get back to clubs after 2♦, without having opener thinking responder definitely has 4 and pulling back.

[pigpenz]

actually i would rather see this as RKCB, since we are bypasssing 3NT.
GIB doesnt like temporizing bids.

[cloa513]

This is more a story of lack of thinking the system. No reason GIB couldn't handle temporizing bids if it was following bidding rules which make it show its hand rather than make a contract decision. It would have to be symetrical so with 1D,-,1S/1H,- 2D,-,3C is forcing with 10+ HCP and 4+ in the major shown.