i think alternating both is a good idea if youve got the cash.
as far as which is better, it isnt really clear.
on the one hand, ahk-cu (the active ingredient in tricomin) has the science and studies behind its CP formulation, but tricomin itself probably doesnt contain a similar concentration of ahk-cu that was used in the studies- if it did, there would be no need for blue dye.
folligen has not been through testing like ahk-cu has, but it contains a large mix of copper peptides, vastly superior in concentration of CP's that, pound for pound, are probably not as effective as ahk-cu. but there are more of them.
for what its worth, ive spent a lot of time reading through threads and various pieces of info on both products, and as far as anecdotal reports go, some people do swear by folligen, but ive yet to see anyone who can clearly say that tricomin has really helped them.