I nearly got seduced by a Samsung Galaxy S6 Edge+ recently, but managed to resist.
Zub: The A9 sounds like it will be a real beast in terms of processing power: http://www.gizmochina.com/2015/09/09/htc-one-a9-with-mt6797-deca-core-chip-hits-geekbench-beats-exynos-7420/. So that's promising.
freitasm: I think the HTC software is way ahead of Samsung. At least it doesn't come with a truckload of "apps" that is of no use.