If you were looking for an older car I would unhesitatingly recommend the Vitara. I have a 1.4 2020. However the newer models are mild hybrids and reviews of that system are not all positive. So ensure you that you like how it drives before buying one.

Dacias are built largely from Renault/Nissan parts and historically these manufacturers are less reliable than Suzuki. The Vitara has recently scored very well on reliability. In practice of course individual cars might defy the broad stats. Dacias are well regarded for the price and owners may make allowances on reliability if they have got a bargain.

As to off road either is probably fine for wet grass and other slippery conditions with the right tyres. If you want to seriously off road I doubt the Suzuki is rugged enough. I don’t know about the Duster. Also you may have already researched their 4WD systems, if not it’s worth looking into how they each work to ensure they meet your needs. I suspect that neither of these is going to cut it as a serious off- roader. Not all 4WD systems are equal.

Finally the LPG in the Duster might save some money but I see fewer petrol stations selling it these days.

Honestly, both the Dacia Duster and Suzuki Vitara have their downsides. They're not the best for very tough off-roading or super powerful drives. They both have good and bad points but don't expect them to be amazing in power or off-road skills. But if I had to choose one, I'd go for the Suzuki Vitara. It's a bit stronger because of its 129HP engine, which might give you that extra push you need for your trips or a little off-roading. It also has a mild hybrid system that helps save some fuel, which is a bonus.

The Duster has a good reputation as an occasional off roader and has better ground clearance than the Vitara.

The Vitara is probably more reliable and a little more sophisticated.

Neither is a 'proper' off roader as they don't have a diff lock or low range gearbox. They'll be fine driving around tracks and through the snow, but they won't be much good for tricky green laning or off road courses.