In reply to rockwing:
I've had Sportiva Boulder X and.now have TX4's. For scrambling and climbing I much prefered my Boulder X tbh. I just don't find the TX4's to be anywhere near as supportive. I'm generally happy climbing up to HVS (grit) in Boulder X but TX4's just don't work as well.
TX4 are probably better as an approach shoe and are less bulky on a harness, but just not as good on routes, nor is the lacing system as good as that on the Boulder X.