If you think you might ever do any diving other than pure open water recreational (in otherwords, penetrate wrecks or caverns or other overhead environments), nix the idea on the BC integrated octo.
The integrated octo's do work as advertised, but I found it's actual use to be a bit too complicated. And by having the TX40 octo, you will have a secondary air source that has the performance characteristics very very similar to the TX50 primary.
And the additional hose/clutter on your BC argument is not really valid until you start getting into the serious technical diving where entaglement is the main concern. Having the "typical" octo with hose does not significantly increase your drag through the water.
The choice to use an integrated octo boils down to a personal preference. But you will see many divers, like me, don't prefer them.
Do a search on this board for topics and keywords such as "integrated octo" and "air2" and you will see what our recent discussion was on these.