Sounds like you are going for the XL650. I have one of those.
It's a fine machine. When you can swing the upgrade to the 650, you will not be disappointed.
I don't view the casefeeder system as an option. Unless you really LIKE stopping every ten rifle rounds to refill the case tube, that is...
When you buy a 650, budget for the casefeeder, beyond a doubt. And make sure that your workbench is very strong and very rigid, because the 650 doesn't take well to being mounted on a flimsy surface. The vibration screws things up. Specifically, the cases will fall over before they get into the shellplate. A solid mount is essential.
Get a big handful of primer tubes, too. Ten of each size you use, at a minimum, then you can load a thousand rounds without refilling any tubes, which is a minor pain.
I'd have to say that the faster the press, the more you'll want to accessorize it. The powder check system is something you'll want as an insurance measure when you're cranking out ammo too fast to visually check each round.
CJ