Ugh, just placed the order haha! I'm thinking I'll use both, but who knows. May end up getting rid of Echo. I'm heavily integrated with Google so may just find Echo unnecessary.
Here's something else to consider. Android Police is saying that Google plans to launch a mini-Google Home that would compete directly with the Echo Dot. Assumption is that it would be cheaper than Google Home but no price point mentioned. £ 75 is a real great deal in my opinion for GH but if you want to fill your house or office with voice controlled interfaces, it would be nice to have an even lower price. This article mentions a new Pixel Chromebook first and the mini Google Home as the second device.
http://www.androidpolice.com/2017/0...-version-of-google-home-alongside-new-phones/