You should ask your questions in the forum where you will get some replies.

not used either of the ones you have said but there are a fair few comments on the 400p if you do a search.the orion for me is way overpriced as you could get a 16" manual dob and add the goto function to it for less.i have a 16" lightbridge,not really tested it much but its promising so far but they require a few mods to make them work perfectly.the lightbridge build quality isnt as good as my skywatcher 300p was!!!the 400p by all accounts dwarfs my 16" lightbridge which is itself huge