The Boost 141mm rear? It is a bit limiting, but not a deal breaker IMO. You can use a boost 148mm rear hub that allows you to swap out QR endcaps, bringing it down to 141mm. Hope support this in the Pro 4, and I think Halo do too among others. I’ve read that the new Shimano Deore range support this spacing too but I’ve not found a QR boost hub from them to confirm this.
I bought a Marin Pine Mountain a few weeks ago and was a bit put off by the rear spacing, but I’m hoping the original hubs last a while before needing replacing.
I did look at the Genesis Tarn and really like the look of them. They appear much more on trend than the Marin, but Rutland had a 2017 Pine Mountain in my size for a very good price. I’ve only had a few rides on it so far but I am loving the plus tyres. Coming from a steel 26er hardtail the Marin is a couple of KGs heavier but is easier to ride over rough terrain so I personally haven’t noticed the weight increase too much. If I had another much lighter bike and rode the two back to back I’d probably notice the weight, but I don’t.