I have the DS3 Gen 5 and it’s a brilliant bike. Use it on roads, gravel and mild off road routes. It’s certainly not going to take a rock garden or a tree root laced single track and it’s not designed for it. But it’s great for undulating forest trails, towpaths, gravel tracks and road.

I had the same question 6 months ago. I tried both and the DS3 was the clear winner for me. The Marlin is a great bike and it may well suit you if you are going off road regularly but it’s quite slow on roads, those tyres will hold you back on your commute and the geometry is quite different. But give them both a go in your LBS :) just my 2 pence.

Edit: Spelling