I currently run 16" load-rated, relatively low-sidewall passenger tires on my Cobalt trailer...Having replaced my camper tires x3 times in 8 years, and boat trailer(s) more than a few times...I think the best bang for the buck are radial tires (as opposed to bias-ply tires). My new camper is running 16" trailer specific, radial tires from the manufacturer.
I ran to and from lake at least 20 trips last year along with the trip from COS to Powell without so much as losing any pressure (I check every other trip).
In my opinion (I know what they say) I think the biggest knock against trailer specific tires is how quickly the UV rays break down the sidewall and as mentioned by Bruceb58 and Sprig...having trailer specific, bias-ply tires sitting on the ground under weight causes deformation and flat spots...I agree.
When I purchased my current boat trailer tires I wanted a trailer specific, radial tire, but there was none made that would fit my trailer/wheel combo, LT tire was my second choice, but again, nothing in the size I needed/that would fit. Passenger tires were at the bottom of the list, he assured me as long as the rating exceeds the load (5,350 loaded/4 = 1,338lbs/tire). Mine are rated to 1,800lbs/tire. My buddy's boat trailer came with very wide, low-profile rated passenger tires as well...3 seasons without incident...granted, he's very anal about his maintenance and it sits in the garage 330days out of the year.
I'm not here to debate the validity of what type of tire you're using...just wanted to share my experience and make sure you know a decent tire shop that you can trust? I'll take a radial tire blowout over a bias-ply any day...the radial was a substantially less frightening experience on my CC, single-axle trailer...