I guess it depends what you're wanting. If you're wanting a faster phone and a bigger screen, then it's probably a good idea. If you're happy with your 920, then there's probably no point in spending the extra cash.
It was a flagship of its time...I owned two of them(Yellow and red) and I loved it.
That being said, compared to a 640 XL, I really cant say the 640 XL is less in comparison to a 920.
If we were talking going from a 930 or a 1520, i't'd be harder to rationalize but with the XL, I think it is a worthy upgrade from a 920 Plus it is likely to get more support than the 920 will(a 2012 phone vs 2015)
I've just done this: yesterday I had the chance to finally see the 640 XL and I immediately fell in love with it. I was looking for a phone with a bigger screen and a bigger battery, so I decided to switch: can't wait for the package to arrive.
Yes, you definitely should. Camera should be better. The fit and finish is really good. I learned it even supports wireless Miracast. Has all if not most of flagship features, like double tap, glance screen, double tap to cut off, etc.
It's a really nice phone and I say its way better than a 920.
With Lumia 640xl you will get great camera front and back also great video playback experience.
Best internet experience with big screen. Premium looks and design.also it has many connectivity features
Great value for money.
But for gaming it's not a good one..I watched lots of review on gaming of 640xl
I also owned Lumia 1320 and 625
Both are great devices.
Lumia 640xl kind a similar to Lumia 1320. It's good for casual games but not for heavy games.
May be you can see reviews.
Final choice is yours...