You seem to be trying to talk yourself out of buying one Frankish!
I admit it will be realllllly tough not to buy one of these at this price point! Very tempted.
You really don't. Most people on these forums are interested in ROM customization and there isn't much chance for that with these Chinese MediaTek devices. Sure there's xposed framework etc these days but you're still stuck hacking your stock ROM no matter what. There's no chance for your favorite AOSP based ROM (CyanogenMod, AOKP, AOSPA, RootBox, PAC, and the list goes on) on MediaTek platform, when there's no such problem with Qualcomm devices. Performance-wise msm8x25q should be in par with recent MediaTek quad-core platforms. And SGX544 GPU used in those is ancient too.
Generally speaking, nice too see Snapdragon 200 devices finally hitting the market in Europe. These are planned as entry level devices so you can't expect miracles anyway. Seems that ZTE has hit a nice price point for that (at least for countries where Nexus 4 is not available at Play Store price ).
I see what you're saying in regards to roms and customization etc i totally get that point. My bang for buck reference is more down to the core specs, screen, slightly better gpu. Some of these MTK phones have an almost fully AOSP 4.2 so are great to buy just AS IS. I bought mine with the aim of installing MIUI as it's officially available.
I'm sure i'll end up with the ZTE though as i say i loved my "San Francisco".