Just setting the heading bug to an ATC instructed departure heading is one thing.

 

But if you disarm Lnav by pressing on the HDG SEL switch while still on the ground, then the TOGA roll mode (which is like track hold for take off) will also disengage.

 

You then have the FD roll bar deflected left or right the whole time (depending on the set heading) and it is quite annoying to have to fight the urge to follow that FD roll bar.

And you are fighthing it because most airlines will follow Boeing SOP which means you want to fly runway track untill 400ft AGL (which is what the TOGA roll mode gives you) and then, above 400ft, you can start turning by engaging heading select mode.

 

 

it is quite annoying to have to fight the urge to follow that FD roll bar

 

Really?  I don't think so but it's an individual preference.  I like knowing I spun the knob in the right direction before the takeoff roll by looking at which direction the steering bar deflects. To each his own.