I've always favoured the bigger mesh as long as the twine has virtually no stretch to it,, think we all used the 4" when the nylon sheets came available,, worked just fine so they did, though the twine at the time had a stretch to it,, many years ago when I was out a few times I used 4 1/2", in 5z nylon,, this sheeting was sourced from the USA,, and it was superb,, minimal stretch and caught really well, one could clean a net a lot faster and I also found less mending was needed regarding repairs, that alone was a bonus,, if any rabbits did make escape then good luck to them as they must have