In Optical quality the Visionary HD 15×70 binoculars have the edge over the Skymasters. Build quality is also better on the HDs
So where else are the differences. Well for starters the Visionary is twice the price, but does have a couple of improvements. I found the “V” imprinted on the Visionary body gave a much more grippy feel to aid confidence. Also the warranty is slightly better with the Visionary. They both have 2 years parts and labour warranties. But the HD 15×70 has a further 8 years “parts only” addition to the guarantee.
The Skymaster comes with a free tripod adapter, where as the Visionary does not.
Both come with the same budget soft case
So summing up, the Celestron wins hands down on value for money. Go for the Visionary HD if you want the peace of mind of the better warranty and superior optics