I found your post doing a search .
So I registered to give you my opinion .
Got two Loadmasters and they both run fine .
At First had some problems but they were not set up right .
I would buy a couple extra primer sliders in case you smash one .
But if you watch the videos you should be okay .
I am sure 550's are Great .
Almost ordered one from Grafs tonight .
But think I will wait for the Hornady LNL
to be in stock .
Can never have enough toys .
Got a SDB but it hardly gets used .
In fact after Dillon refurbed it this Summer I
have not used it .
Don't think that I'd be comfortable with manual indexing .
Look Here http://loadmastervideos.com/
Good Luck in your choice , Bill