hi Dave and welcome , the 2 scopes you are looking at are made in the same factory in China , " Synta " Optically the should be the same as they probably came off the same production line ,
and thats where the problem lies , Mass Production has very little QA ( quality assurance ) .
Sad but true ,Dave .
Both Sky Watcher and Saxon do there own QA on there scopes before sale to the public but , it's only the name and colour that differs , so both are very good for the price ,
I own both in the 150mm size and are very happy with both .
For lunar / planatery use a 120mm is awsome , and good on deep sky as well .
but as Malcolm said an 8 inch Dob will gather more light and show fainter objects
its up to what you prefer,Mate.
On the sky watcher / saxon , for the money look at the acessories like eye pieces , finders , mounts etc . these all add up to a good usuable scope .
Hope this helps Dave .
and above all mate enjoy.
Brian.
.