You can pick an overpriced 6'' phone, there's a dozen of em now, but as said, nothing will come close to the 1520. Im in the same boat as you - had my 1520 for 4 years or so now. It still works pretty well, a few scratches and the screen is giving me some problems (because I had it replaced with some "cheap" part), but it's still zippy. I'm looking at some other phones, and I realize that for ~400€ (which is how much I paid for the 1520 at the time), not only can you NOT find a better phone, you can't even find one that's as good. I personally have no plans to throw nearly 1000€ down the drain for a phone that is barely better if at all, so I'm still waiting for something good. I suggest the same to you. And you'll know it when you see it, just like with the 1520, even when I heard the first rumors about the so called Bandit, and the first leaked pictures, I had a feeling that thing will be sick.
If you don't wanna do that, just pick any crappy Android, they're almost all the same.
SG9+ or the newest Note (whichever one it is) is your safest bet, though you can save a lot of money with a Nokia or a OnePlus. Not impressed with LG, and the Blackberry which someone mentioned - only go for it if you're really into that kind of thing. As for Huawei, their phones are kinda cool and cheap-ish, but the OS is dog-poop and the support is questionable.