I have owned a few over the yrs
Pro's
simple, cheap, light, pull easy, easy to move in off season or??
Con's
snow build up on top, can make tilting them HARD or impossible IF they also freeze to deck
they are NOT as dry on inside as many other enclosed trailers by design
tying down ski's can be harder pending access door or not, and MOST EVERY access door I have had , after a few seasons IF that long, start to leak
another thing, PENDING WHAT trailer, is smaller tires, that DON"T have higher speed ratings and IMO seem to get more flats(or I have sure had more on these types of trailers than any other type of trailer I have/owned)
and last, but on tires, Most of all my 4 way lug wrenches I have, the clearance between ground and deck of trailer is never enough to allow me to spin a 4 way, they hit the road or the decking more times than not
but this varies from trailer to trailer, some the deck sits taller and some have taller wheel/tire OD's
I simply carry a cordless impact to change flats now too, so problem solved pretty easy or, get a smaller 4 way to have if needed!
LAST CON I have for a clam shell or ANY very shirt length trailer is, they are harder to back up, as smaller inputs from steering seem to make larger changes in things or just faster LOL
but with some practice there not that hard to do!
I will also add this, just because
BUT almost every clam shelll and like trailer I have had, the axles rust out at about 7 yrs or sooner(some a little longer) but 7 yrs seems about average for me in a super heavy salt use area, no matter HOW often I wash clean oil things(galvanized axles a little longer but not perfect)
its at the mounts where the axle mounts to trailer that get rusted out, so if buying used, look REALLY good at the axles and where they bolt onto trailer, as well as trailer frame where axle bolts onto axle, two different types of metal never play nice and can be BAD in these area's
and MOST 8.5x10 clam shell trailer will NOT fit any 136- like sleds, (some don't even fit 129 sleds)and even some 12 ft long one's , pending HOW the shell is formed and how much room there is for the NEWER Taller sleds we have now as to yrs back, the nose on sleds cannot go as far forward at times on some clam shells, so rear of sled won't allow clam to come down and clear things!