You'll be able to control Alexa through anything you can now.
Depending on what you want to do & what you put on the pi (software wise) you may be able to do so much more.
I've mounted a zero W board into several CM15As now. These all run the PiX10Hub image (includes HomeGenie and HA-Bridge) I have one at my off grid place and one at my city place these do everything AHP did plus so much more. I can access every thing with anything that has a browser.
HomeGenie has a free Android app and a $5 version. I've used both, the $5 version is well worth the price.
The one big difference is that with Alex10 you have Mr.T's nice Windows program to manage your devices as a front-end so you don't have to work directly with HA Bridge. With the Pi you'll be working directly with HA-Bridge.
Actually HA-Bridge now has a HomeGenie helper which integrates HomeGenie devices directly into HA-Bridge with simple mouse clicks.