Look on Makeupalley.com to see reviews and compare the two. I've never used either products. However, I've gotten my hair into MUCH better shape by using these two products:
Frederic Fekkai Protein Rx Reparative Mask (expensive, but smells amazing and restores strength to hair)
Joico K-Pax Intense Hydrator (smoothes, hydrates and helps prevent split ends.. I use this every three days now and my hair has never been better)
I have tired both and I personally like Wen better then Ojon. Ojon made my scalp itch like crazy. However, Wen is so expensive in my opinion. Wen did improve my hair though. I think Wen is worth trying out.