Well, again, unless you don't use it professionally, I think a grinder for 100-200€ (like the two I just named) will definitely do the job. Other than that, it's mostly noise reduction, ceramic "grinder" and some fancy stuff like timer(s). Also more compact design, resulting in less space for old coffee grinds to settle (the Vario II has, I think, about 2g of ground coffee, which is pretty good -- some have like 5g).
As to boilers -- unless you drink cappuccinos en masse, you won't even need a heat exchanger. But dual boiler is a complete overkill for any purpose with just one brewing group. Don't you think so?
As far as I can tell, the Brevilla Dual Boiler just has all the gimmick stuff included. You can always upgrade a Silvia with a PID, pre infusion thingy (both of which aren't a must for any beginner, but probably actually unproductive), and you can use a simple timer switch. Edited by b1os - 8/29/12 at 3:04pm