I own 2 Pro 2019 models and since last December a Pro 2026.
So I can’t compare with the Pro 2023.
AFAIK the only difference is the 2026 having twice amount of RAM, 4GB, which allows you to run more apps / run more apps which use lots of RAM.
This has zero impact on speed or reliability.
About speed: that would be about the experienced User Interface speed.
On performance level (executing flows, response to sensors) I don’t see striking differences between Pro 2019 (WLAN) vs Pro 2026 (LAN), but that might be different when it has to handle lots of zigbee/z-wave/Matter devices.
As I surprisingly discovered, the app or web app are not that much snappier / quicker compared to operating the 2019 models.
Using a phone, a new-ish tablet or a laptop doesn’t make a difference.
Homey is still the slowest phone/web app amongst every other app / interface I use.
And, eh, yeah I still like Homey 
And I even don’t use Homey’s zigbee, z-wave, Matter-over-Thread.
Conclusion: only if you need to run more apps, or RAM hungry apps, a Pro 2026 is more suitable.
You’d also know the possibility to updrade your Pro 2023 to 8GB RAM, by modding it
But, that involves DIY, patience and good reading skills; and possibly losing warranty, and the risk of bricking it.
https://community.homey.app/t/modding-various-homey-pro-early-2023-modification-suggestions/79487
