If you are comfortable with knitting in the Combination method than I would say to stick to it; you will just end up doing a few more steps than someone who knits in Continental or English method. If you would like you could learn to knit in the other forms so that muscles in your hand(s) do not tire as much from the consistent use in that manner. Also, have you taken a look at Annie Modesitt's web site for Combination knitting. Just go to anniemodesitt.com
Welcome to the adventure.
Judge: Madame, either you will have to cease knitting or I will have to cease judging. Which shall it be?
Miss Marple: It helps me to concentrate, milord.
Judge: It does not help me, madame.
Miss Marple: Oh. Very well. (puts away knitting)
Judge: Thank you, Madame.
The lyf so short, the craft so long to lerne.
~ Geoffrey Chaucer - The Parliament of Fowls Line 1.