iPhone 6 11.1.1 .... is still slow..

Has anyone had any luck with the freaking update 11.0 and then 11.1 and then 11.1.1 My phone is so slow. I tried all the tips and suggestions provided, but still don't see any changes improvement in speed.i have around 5 GB of free space available still slow..but my question is why should I disable all my background refresh and other stuff

can anyone give any thoughts or suggestions..?

I used to have all apple products, I am slowly moving away from Apple products. I am really frustrated with the price we pay for these gadgets and have to keep upgrading gadgets..