I love mine, but like any phone there are compromises in the design. Whether those compromises will affect you or not depends on how you use your phone. I bought the phone because I loved the front-facing speakers and the brightness and clear resolution of the screen. I've had Samsungs in the past, and I don't care for AMOLED with the oddly supersaturated colors, poor daylight visibility and burn in issues.
Like any manufacturer, there can be bad batches. I recommend buying at the store so you can look for defects, build quality issues and dead pixels before buying.
Mine is still stock on 4.1 and it runs a bit warm. The metal housing means the heat is more noticeable than with plastic phones. It heats up quickly, but cools down quickly as well. Around here the ambient temps here are around 65 to 75F indoors, 90F+ outdoors. My battery monitor app says it is running 85 to 90F idle indoors, 100 to 105F under load.
T-Mobile larded their stock ROM up with bloatware, so I'm sure there's a bunch of crap running I don't need or want. I've heard that's less of an issue on stripped 4.2 builds but I haven't tried rooting yet. Official 4.3 is due soon.