Hi,
after having followed SICP, I have been irremediably hooked on Scheme's let, so I added it to my macros. IIRC, I borrowed this implementation form SBCL's NAMED-LET (it's so short, it's hard to tell).
I also heavily use a cataphoric IF, which I will now replace by the single-binding IF-LET, now that I know it exists.
I thought it would be nice if LET@ was available in Alexandria with the other binding macros.
Regards, Pierre