I had the same thing at DNS - the CPC is high but the CTR can be hit and miss.
If your main focus is parking, not sales, then it makes sense to use a company that is dedicated to parking. Bodis, Voodoo and ParkingCrew all fall into this category.
Your question was who has the highest CTR - in my experience (for my domains) if you give ParkingCrew adequate time (i.e. weeks) to auto-optimize you will see good results. If you have the inclination you can also make domains on Voodoo look almost like a mini site, as they allow you to change the colour, layout and picture. This can probably lead to an increase in CTR, although you will see good results with Voodoo anyway.
Bodis is a good 'hands off' type solution. Point and go.
You should try all three, and give your domains enough time on all three to make a decision where to park each one. I'm only just figuring this out after 18 months.