Yep, I'd swap ALDA's. Some cars will require loosening the rear three metal injection lines to allow the ALDA to come up & off the IP (some cars don't need this - each is different). If the car runs great with the "good" ALDA, you've found the problem, and just need to buy a used ALDA from a 617 or 602/603 (~1980-87). While you're doing that, try tweaking the ALDA, turning the setscrew about 0.5-1.5 turns CCW. The car should jump off the line pretty strong, and you should NOT feel any "hit" of power as boost builds - it should be smooth & seamless (strong enough off idle that there is no "hit" when the turbo spools.) Only turn it up enough so you get the power gain, go further and MPG will suffer.
About the boost pressure. 10psi is a little low, but it could be a weak wastegate. Spec is 0.85-0.95 bar, which is 12.3-13.8 psi. No ALDA enrichment can cause low boost too. Also, as Speedy said, 10psi can make for a plenty fast car if everything is perfect. My 1984 only makes 10psi, and cranking up the boost to 15psi gave ZERO power gain. More boost does not always mean more power...!
HTH,