I have just made switch from a galaxy s5 to the xperia z2 and it is definetly a better phone. Ive had a lot samsungs (every s/note phone) since the s2, the lumia 1020, iphone 5s, htc one m7 and feel like Ive finally found the sweet spot. Personally i dont have that much problem with samsungs lightweight plastic design but their software is awful and we are at a stage now where it Will never get any better. I nearly opted for a one m8 but that camera! Stops the phone from being at the top of chain. The z2 feel like the best combination of a simple software that doesnt use every colour from the crayola pack and a great camera. Just my opinion but i think youve made a great choice 
