I own and use a variety of hardware options, and have owned a few Surface devices (and still own one... I think it makes a great netbook but an inferior tablet).
My current primary mix of devices focus on an iMac, 12.9 iPP, and an Android phone. The 12.9 iPP has replaced my 11" Macbook Air + iPad Air 2. For those times when I am away from my home office and need to do work on OSX, I use my iPP to remote desktop into my iMac. That has worked out very well so far... it will be even better if/when Apple natively supports mice/trackpads or I bite the bullet and buy the Citrix X1 mouse.
The 12.9 iPP comes closer to the converged device sweet-spot for me even though it falls slightly to the tablet side of the spectrum. The Surface devices fall more heavily on the notebook side of the divide, falling shorter as a tablet than the iPP falls short as a notebook. But it is absolutely down to personal preference and workflow.
I am just curious why with that set up, you use an android phone? The reason I ask is that I have thought about doing something similar mainly because I would like to try a different phone such as the Sony or Samsung phones. I would just hate to lose the iCloud integration between all of my Apple devices.