I'm on the -145 and I have a handful of friends on the 175. I've been upfront on them a handful of times as well. Going from the 175 to the 145 wouldn't be terribly different. There is less automation than on the 175. As long as you aren't flying the legacy, there is no Vnav function of the autopilot. We don't have any Vnav abilities besides being able to build a slope off of a fix and creating a 'carrot' on our PFD. This is only available in long range nav/FMS mode. You can go through a series of pages on the fms and get a little bit more detailed display of exactly how far above and below you are from that slope, but some people don't find it that helpful. Also when it comes to automation, there aren't any auto-throttles. It does still have a FADEC so it's not like flying a -200. Besides that, the overall cockpit is pretty much the same. Smaller and much louder but everything is in the same place. I think the transition would be extremely easy coming from the 175 vs any other aircraft.