An aggressive all-terrain like the two models mentioned are both excellent for a Subaru and I can't imagine that you'll really notice a substantial grip difference in the muddy or clay type surfaces with the light weight of these things. I don't think there's enough benefit to getting the chunkier mud-tyres as they're so noisy and not much of a fair compromise. That said, you can get some BFG muddies in just about any size you want. Price and ease of finding a store with stock is much easier with a 16" rim. Definitely stay clear of the highway biased stuff simply because it clogs very easily, but the more open tread pattern of the BFG KO2's are my pick. I've tried a lot of different off-road tyres to my cars over the years and the KO2's are a much better compound than they used to have in the original version (still on sale here at the same time as the newer model for very little difference in price). The newer compound has much more grip on wet tarmac, much quieter than others, and yet they're still excellent offroad. I'll be putting my money where my mouth is and getting some myself in 225/70/16 fitted to my SH Forester quite soon.