Warren, you will not have an issue in sticking with the Lux. With all of the stuff written about grinders it is easy to be frozen into doing nothing or going completely overboard. The major task the grinder has is to produce a consistent grind with a minimum of fine dust particles which tend to increase bitterness. You also want consistency from grind to grind. Grind consistency is related to the type of burrs used and the ability of the mechanism to securely locate them when the grinder is doing its thing. Generally, the better the grinder, the tighter will be the tolerances and therefore the less play in the burrs (i.e. relative to each other). Then you have other variable such as doser/non-doser, ergonomics/ease of use, fineness of adjustment, repeatability of adjustment etc.
Even though you might contemplate changing the Lux later, it will be a very good start that will enable you to find your way to making consistently good coffee with the Silvia.