I have a close Chinese friend who listened to some of the recordings on my IPod - she said go with CLO. She constantly remarks on my great accent which she says is always the biggest problem.
I travel a great deal and knowing Chinese, even a little, can only be helpful when 1/4 to 1/3 of the worlds' population speaks Mandarin Chinese. You are doing a great job - I seem to be going very slowly; however, my friend says I am not but rather she is impressed with where I am and again is most concerned about the correct accent.

I think your course is well organised and is great for beginners as well as more advanced. I've only listened to about 30 lessons so far. I like that at any time I can review lessons. It's also great to be listening to native speakers. Unfortunately there is no short cut to learning a new language especially when it comes to tonal Asian languages. Conversation context is great.

Seeing the pinyin makes a big difference. I like to picture it in my head when composing sentences and having the tones works helps a lot. Your product is great! Especially now I can visualise the tones.