To Realidades or Not To Realidades?

I just got this from a PLC member and I know I’m taking a break from the blog but this is important so please comment back on it if you have some thoughts:

Hi Ben –

I’m feeling anxious about [pursuing comprehension based teaching], especially since I recently helped fill out a purchase order for a 6 year license for Realidades textbooks for our program, and now I’m not sure how much I should be teaching from it. I think it’s a good textbook, but can I mix the two – doing some CI and TPRS, etc. and also using the textbook for some activities, culture, etc?

It may already be too late, but I wasn’t sure if I should try to stop the purchase of the textbooks or just let it go through. Any thoughts?