Smartphones screens come in all sizes nowadays from the small and humble to the big and bold!
What is the ideal screen size for your needs?
I’ve been using my iPhone 7 for the past couple of years and the 4.7 inch screen is ideal for me as it’s just the right size for my needs as I tend to consume most of my video on my iPad or smart TV and use my phone for general purposes.
Discuss away ladies and gentlemen 
I was once recommended that the ideal screen size is the one where if you lay your phone flat in your hand you can place your thumb from one side to the other with limited strain. This maximizes your usability without make for cramping. My V35 is a 6" infinity screen, perfect for my hand size even with a case installed so I cant complain about that advice.
My Essential PH-1 has a 5.71" screen.
Which coming from the Note series of phones is about the same, although the footprint of the phone is much smaller.
I think that edge to edge displays are and will be more prevalent. This size is plenty for me and note sure that I need the 6.2-6.3 of the Note 9, iPhone XS Max, Pixel 3 XL.
The price differences to upgrade are crazy.
I still love the size of the iPhone SE, perfect size to use in one hand!
I like my 50-inch UHD TV. It fits conveniently in my pocket and it’s easy to share with others in public places. 
No seriously I have a 5.5 inch moto z2 force edition and I wouldn’t go any bigger. Mostly because I like to carry it in the side pocket of my Carhartt dungarees:
Any handset that doesn’t fit easily in there isn’t going to work for me.
I love size of iPhone SE. Anything bigger is inconvenient for pocket.
I prefer the larger 6.3 inch infinity display on the Note 8 note 9 is the same size but with a 6.4" screen and smaller bezels so that would be cool too. I think the biggest factor when choosing phone screen size is hand size and how much media you are consuming on the phone.
My Note 8 is like having a 65" tv in your pocket if the phone is about a foot away from you face like when you are laying down.
I just upgraded to a phone that is about the size of the new note 9 (LG v20) and it is a little hard for me to use that phone since it barely fits in my pocket. It’s only a 5.7" screen but still its huge! I was coming from a phone with a 5" screen. I think 5" was a nice size or a 5.5" with no bezels would be good too! I’m not a huge fan of these bigger smartphones coming out because i can barely use them well enough with my small hands lol.
What kind of case are you using?
I had a few cases before I found one that wasn’t too bulky in my pocket but still offered good protection.
I like uag cases and have used them for about 5 or 6 years now on multiple phones. They are thin, light weight, work flawlessly with wireless charging, offer pretty good protection and come with a screen protector. I haven’t cracked a screen since I owned a iPhone back in the day despite some pretty nasty tumbles.
I also had a Trident case that was great when I was doing construction but a little overkill if you’re not on a job site or an outdoors man/woman.
For me I can’t use a case since it barely fits in my pockets without one. I did buy a slim ish clear case just for a bit of protection and just found out I can’t well carry it around well with small pockets if I don’t want to carry a bag with me. My phone is definitely harder to use with one hands and if I were to buy a new phone it would def be smaller. I think I might just slap a skin on it and just hope it helps a bit with scratches + better grip.
I’m using a very slim phone case that practically adds no bulk to my phone whatsoever. But on the flip side offers not much in the way of protection.
Thankfully it has got a really good grip on it and i rarely ever drop my phone and never smashed a screen. 
The iPhone 5s (and SE) was probably one of my favorite sizes as far as being pocket-friendly and easy to use with 1 hand. I love my iPhone X but it can be difficult to use with one hand (and it makes the iPhone 5s’ screen look minuscule).
That’ a nice upgrade @TechnicallyWell I’ve done similar, iPhone 5s to iPhone 7 and it is really strange running with that screen size jump, I mean it’s wonderful to have the larger clearer screen but I do miss the compact slickness of the 5, it was a great allrounder for size, ease of use 
I use to have a Galaxy S3 and I jumped to the Moto X Pure edition. That was the perfect screen size for me and my large hands, and while it was a big jump I loved it. Now I have a Galaxy S9+ and Its a love hate relationship, the Moto X our was a normal screen aspect where as the S9+ is more elongated so I have to reach more to go top to bottom. But I still prefer the larger screens because I never have an issue fitting into my pocket…baggy jeans for the win
The iphone X size of under 6" is perfect, anything larger just use an iPad.