Ok so a week has passed and here are my thoughts:
Am I missing my 17" 2011 MBP? No, not at all - I have just used it once since to transfer all my stuff and that's it!
Keyboard: At the beginning was a pain in the a** I admit it even if I didn't expect it, but after just 4/5 days I got used to it and now I am back at typing really fast with it. It's actually strange using my 17" old-style keyboard now!
Trackpad: Not much of a difference between the old-style trackpad. It actually just gains features and size therefore it's a plus in everything!!
Screen: 4" diagonally smaller is A LOT! This actually was my biggest threat, however I don't feel the smaller space at all! It's a beautiful display, text and images seems like coming out of the retina display this small machine has, the resolution makes it a perfect companion for any type of work I need to do on my new rMB!
Speed: This was another factor coming from a MBP. When I ordered it I thought it wasn't much of a pain having a 1.3 core, however towards the end of my "waiting days" I thought I did a big mistake ordering it by reading reviews here and there and threads on this discussion board. However as soon as I used it for a few days I am now in love with this machine! Not only it handles all the tasks I throw at it that I used to perform on my MBP, but also it seems a lot quicker than my MBP! Not only heavy tasks but also simple web browsing seems to be faster, application opening is quicker, switching between spaces and apps is smooth and quick as well! (I have installed the 10.10.4)
Noise: Since I have been using this amazing rMB I don't know what noise is anymore! I was used to have a big fan noise at some point of my days (actually during several points of my day it just started of with the usual fans and the MBP used to be boiling hot that sometimes I couldn't even put it on my lap! My new rMB is so silent that sometimes I don't even think it's on but I think it's sleeping! And the best thing is that is always cool and the performance is still amazing!
So... so far it's an amazing product and the switch I have made is the best I have done so far! The rMB is so light that it makes it carrying it around a joy used to a heavy bag!
Would I go back to a 17" MBP, never ever ever! I am so happy with my rMB!! If I will ever need more desktop space I will just buy an external monitor, but even that, I thought it was vital for me and that I had to buy it as soon as I received this small machine, but I realised just using it that I don't need it at all at the moment! Probably it will be a future purchase I will make but for now I am so happy that I don't feel like spending any more money!