World Expeditions tours?

Hi all, I am well-travelled in Africa, the Middle East and Asia, and I'm thinking that Central Asia should be my next area of exploration. Has anyone done a World Expeditions (Aust. tour agency) tour of anywhere in Central Asia? I am looking at a couple of their tours, and wondering whether it's worthwhile using them or should I just travel alone. The problems for me are time (I will only have about 3 weeks off work), and also I'll possibly be travelling with my Mum who is 73yo. We're used to roughing it. Also, have any vegetarians ever travelled through Central Asia? I believe a lot of meat is involved at meal times. Thanks in advance for your help.