These are near or same as Galaxy Note 3 performance in normal usage, but heavy gaming is not better than Galaxy Note 3. Budget phone normally compromise on graphic chip.
You may still play smoothly, but will experience frame drop, or lower quality rendering.
Then, budget phone do compromise on other area like screen quality, additional feature like IR blaster, NFC, speaker loudness, lack of Micro SD slot, lower battery life, worse camera, and build quality too, not just the performance that matter.
The lagginess of phone all lie down to processor performance and software optimization, RAM at least 2GB will be sufficient.
So far, only the original ASUS Zenfone 2 with Intel ATOM z3560 or z3580, Oneplus One,Oneplus X, Xiaomi Mi4, ASUS Padfone S with Snapdragon S801 processor, or some cheaper phone with at least Snapdragon S800 processor able to be better or on par with Galaxy Note 3's Snapdragon S800.
Seems last two year flagship is sometime much better than current mid end smartphone nowadays. It's much easier to get accessories too. And lots of rom development in xda too