New dog/ ugly dog vest?

Just a thought.... How old is the dog, and has he ever run with a vest before? Ive got a 6 year old finished cur thats exactly like you described. The previous owner ran him in a vest for years and couldnt figure out why the dog wouldnt hunt. When i got him i hunted him the same way the previous owner did, til i got POed. Took the vest off collared him and turned him out. just like that i had pork in the freezer. I know not every dog is the same just some food for thought. Oh and to answer your question Ive never tried the viper vest.