Is the Forerunner 255 a good watch ?

I buy it !
Until  now it gives me satisfaction, although it's quite tricky to understand some logic of the menu and to get used its handling.
Two things I still have a lot of trouble with the architecture and organization of the softwares for connection and synchronization with the smartphone and the laptop. Why do we need 3 software  (Connect mobile, connect web and Garmin express) ?   I can use WhatsApp either on my phone or my laptop, I can use mail without any problems on both device, etc.  Why the watch, the smartphone and the laptop do not communicate by Bluetooth through an unique software ?

Some people prefer laptops, some prefer phones. You don't need to use both. I hardly ever use the phone for anything that has to do with Garmin.

I understand that people prefer laptops or phones, but that doesn't explain why the watch can't easily communicate with both. Personally, I use both depending on where I am and I'm sure many users do.

But the watch CAN easily communicate with both, so you can choose which one you prefer.

I’m very happy with it and a huge upgrade from my 245. 
Only niggle is with the more expensive 265 launched not that long afterwards how many upgrades will the 255 get? 

Can you send data from the watch to "Connect web" witout using Garmin express ?

If you have the Music version, you can sync directly with Wifi. 

Unfortunately I don't have the music version.   It's a pity tha we can't sync with bluetooth.

Yes, I remember my old Fitbit had a USB bluetooth dongle that could be used to sync the watch. Unfortunately the dongle was very poorly built (like most other Fitbit stuff), so I got new ones regularly on warranty.