I took the plunge on the Steam Deck in the end. Funnily enough @Mel81x's reasons for why he didn't feel the need to buy one swayed me as the games I play don't work on other handheld devices.
For modern games it has been really good. Hogwarts Legacy for example works really well and other games I play have no issues. The only complaints are that it is bulky and the battery life isn't very good.
Obviously I wouldn't purchase thus if I wanted to play games older than 15+ years ago as there's various more cost efficient handhelds that play those games really well.
In typical fashion Asus released a video for there handheld the day after i bought a Steam Deck which is less bulky but can't compete with the Steam Deck on price. So I think I'll get a couple of years out of this.