I've not ever found myself wanting with my P8. For most benchmarks it does well. For some it has been shown to be below par, but it hasn't made any difference that I can see day to day.
I am not currently playing that many games, but if I run 3D benchmarks it seems perfectly smooth and frame rates are still high. As usual, the biggest problem on any device with such power under the hood is that heat starts to throttle things. The Honor 7 has been designed to dissipate heat more effectively, and given the problems with anything using Snapdragon 810 I am really quite happy NOT to have a device that has a more powerful SoC.
Bearing in mind that I am now very happy to use devices with just Snapdragon 400/410, the Honor 7 can hardly be considered 'not good' in the GPU department. Not as good perhaps, but does everyone need a device that scores 70,000 on AnTuTu?
It might not score as high as some devices (of which some still likely cheat the benchmarks) but I suspect the Honor 7 will probably have a score on AnTuTu that's well over double that of, say, a Moto G - which is a perfectly usable device.
You'd have to be down to devices selling for £50-60 to find something that I'd argue was not up for the job. There's NO WAY ON EARTH anyone has to now pay £800 for a smartphone unless they're happy to throw money away in the name of fashion, which is the main reason people are 'happy' to buy luxury goods.
There's no harm in someone buying a Galaxy S6 edge+ for that sort of money obviously (it is a very nice device, don't get me wrong, with a screen that gets 'wows' from just about everyone who sees it), but don't kid yourself that you're getting something 3 or 4 times as good as what's now coming on to the market from companies like Huawei/Honor, Motorola, Wileyfox, OnePlus, Xiaomi etc.