Between Prime and iHeartRadio we haven't felt the need to get any more music sources. I think we listen to iHeartRadio probably 90% of the time. By the minute, playing music is the vast, vast majority of what Alexa does. As with you, apparently, she's in our kitchen which makes her very handy. Changing music or setting timers without cleaning hands is - for us - worth the price of admission. All the other stuff she does is just a huge bonus!
I really need to make a home automation plan. I'd used X10 since way back in the day, but when they added Wemo support to Alexa, I grabbed a few modules to replace the X10. I hate Wemo, I think it's awful, but she doesn't have a problem with it and now I'm invested. I need two more, and I'm about ready to just buy more Wemo instead of investing in something more powerful. I feel like my choices are either throw $100 on more Wemo stuff I *know* I won't stay with, or chuck out $500 on any grander solution. Hard to justify that $400 spread.