Sailun S-637

So another question. From what I gather when talking w/ the chap from Sailun the "old" Sailun's were LT rated and I'm quite positive he said the new ones are ST rated. I'm one for LT tires and I recall the article Trailer Life did and how they ranted and raved about ST tires over LT ones. So GY's are LT along w/ both Kenda and Van Guard (latter 2 I'd be leary of for use in RV market). Sailun's sake of argument are ST rated. If the data label calls for LT's and Sailuns have a pretty good track record so far, given same weight ratings as LT's, still okay to put on? Limitations of ST in this ply? How do you know if they will fit (larger circumference than GY)okay before one has tire shop/online get them? I know like others have said, we could argue till the cows come home as to which brand is better, but would putting on ST's vs LT's be a really bad idea? Based on what I've been able to research, both GY and Sailun's seem to be the only 2 real players in the 14 ply market with one being a LT and the other a ST. FWIW (still dickering w/ seller/dealer on $$$ diff), the "new" or new to us coach has a GVW of 15,800.