This is a great work station, much better than the one I built myself! :-) It has no flaws whatsoever and for the price you could not think this was as great as it is!
If there is one comment I would make it is that the lowest working slope is not low enough. The makers could move the furthest support gap (to flatten the item) a fraction further back, and smaller, leaving enough space to make one further support gap for a lower working slope. Just an idea, but I have noticed others have been complaining about this, too.
Otherwise well done on a great and affordable product that is definitely worth having!