I've been using a Lohman cover for 9 years now. I built a strongback or ridgepole setup of 2 x4 & 2 x 6 which bolts together.
Reason is the poles that were originally supplied punched through from our, once in a blue moon, heavy, wet, sticky snow. Now the cover support is continuous.
He strengthened the pole support areas quite heavily but the poles, 2 of them, poked through. Darn snow.
It has been a good cover. Not perfect, but then short of a shed or boathouse and even those are not, it has done a good job.
We chose the grey rather than the blue. A friend went with the blue and it does not show the stains from the winter rains and birds.
Next spring I will send it back to him for a checkover and a modification.
I will add that in my case the cover , once it's on , it's on. Not only from the cover removal aspect but I fully winterize the boat so no pretense of winter trips any more. We miss that as we winter boated for many years but it's a choice we made to do other things in winter.
Lohmann Sails and Covers Ltd making custom design winter and all season boat covers