Welcome to the site
They are popular hills indeed. The only thing i would say is to chose your route first- the steep route up Beinn Ghlas, and then onto Lawers is the route I used. It gives you the advantage of heading downward at a less steep angle at the end of the walk. The route round the traverse path to the bealach is ok, but the descent down Beinn Ghlas may play some havoc with persons with weak knees
The choice of route can be decided after the gate- left or up
A fine walk in both directions. Hope this helps.
Here is a link for my report;
http://www.walkhighlands.co.uk/Forum/viewtopic.php?f=9&t=19400