Bowen is great for getting tested because they actually use darkfield microscopy to make a visual identification of the spirochetes themselves.
Igenex is also great for determining in more detail certain aspects about the disease, i.e. recent/older infection. The different bands on the Western Blot (that's the best one for Lyme) can give insight, and unlike other labs, Igenex seems to handle their samples right. Also, if you test CDC positive through a Western Blot, your doctor by law has to report your case of Lyme.
For me, I first got the Bowen, just to know if what I suspected was true (hoo boy and it was). Then I found a fantastic LLMD (Lyme literate Medical Doctor) who uses Igenex to get more details. I was also CDC positice on this one and also tested positive for Bartonella. Bowen I think only tests for Babesia and now I can't remember if they do Erlichia, but anyway, both companies have merits.