Smartphone Questions & Recommendations 2018

Wanting to upgrade from my broken, slow, unresponsive BLU R1 HD (2GB RAM, 16GB MEM).

I'm really hoping someone who has studied the different CPUs and GPUs of these smartphone could tell me if some of the cheaper ones are good enough.

And do I need Android 8.0 or will 7.0 bee good enough for a few years?? Why can't I just update 7.0 to 8.0??

ASUS ZenFone 4, 5.5-inch, FHD IPS, 4GB RAM, 64GB storage Dual SIM, Unlocked Cell Phone, US/Canada Warranty,Moonlight White (ZE554KL-S630-4G64G-WH) - https://www.newegg.com/Product/Product.aspx?Item=N82E16875220059&nm_mc=KNC-GoogleKWLess&cm_mmc=KNC-GoogleKWLess-_-DSA-_-CategoryPages-_-NA&gclid=Cj0KCQjwlv_XBRDrARIsAH-iRJRw24DI7rydSJJvh9qqPLwck2864DFOkp4iDi9Wg4r5aJ0guqo-hE8aAkVMEALw_wcB&gclsrc=aw.ds

ASUS ZS551KL-S835-6G64G-B ZenFone 4 Pro 5.5-inch FHD IPS AMOLED 6GB RAM, 64GB storage LTE Unlocked Dual SIM Cell Phone, US Warranty, Pure Black - https://www.amazon.com/ZS551KL-S835-6G64G-B-ZenFone-5-5-inch-Unlocked-Warranty/dp/B0756JGS78/ref=sr_1_3?ie=UTF8&qid=1526744609&sr=8-3&keywords=zenfone+4+pro+zs551kl&dpID=41bnVkEAkbL&preST=_SY300_QL70_&dpSrc=srch

Others looked at were the Samsung Galaxy S7, S8, and S9.
 
Solution
I could answer your question about Android 7.0 and 8.0, but not really sure about the rest lol, I'm not a major expert when it comes to phone specs

Yes, you can have 7.0, 8.0 is not a requirement, I still have phones that I use that are on Android 4.4.2, and one on Android 6.0.0, you don't need the latest version of Android unless you want a tiny bit of more performance for your specific phone and security updates, but it is up to you

ChaoticWolf

Honorable
I could answer your question about Android 7.0 and 8.0, but not really sure about the rest lol, I'm not a major expert when it comes to phone specs

Yes, you can have 7.0, 8.0 is not a requirement, I still have phones that I use that are on Android 4.4.2, and one on Android 6.0.0, you don't need the latest version of Android unless you want a tiny bit of more performance for your specific phone and security updates, but it is up to you
 
Solution