I'm thinking of upgrading my device and Moto G seems to provide good value for money, but I've heard it's fragile. Is it a good upgrade? I currently own an HTC Desire X. It works fine and does the job, but many apps are starting to require more power and internal memory and the phone is going slower with time. Is saving up for Nexus 5 a better idea? I need a device which would work fine for a few years. Thanks.