Aspire has a very short learning curve, you can pretty much start making stuff without cracking the manual, the on line forum is active and dynamic. Aspire has 4th axis capability.
Enroute interface is a little gnarly and not intuitive, but it is very powerful, learning curve is steeper.
I bought both Enroute Pro and Aspire, used Aspire for the first 6 mo. or so and am finally digging into Enroute, as the automatic toolpathing capability is needed for the cabinet software I've bought.
Not an endorsement either way, if I was just doing carving and signage at a low volume and wanted to get going quickly (as I did), I'd keep my Aspire, for a production tool I'm moving to Enroute, mostly for it's ability to create operation templates.
I like Aspire a lot, it's a fantastic value for the cost.