When you make only wheel links than your sites go down. Some time google remake it in blacklist. I always used wheel links but in small quantity. I also give actual page pr links to my sites. I rank my site in 1st page in google search in a 15 days, I have done this many time. We should not only concentrate on wheel links. But wheel links is useful.
I did create linkwheels in the past but it seems that Google don't favor them. Most of my linkwheels were de-indexed by Google after the recent Panda update. I don't think it will help you much in the time to come.
for me having high pr domain used for link wheel is very effective rather than using free subdomain sites like blogger, wordpress etc.