That Husqvarna 2346XLS would be worth considering with its locking differential and Vanguard engine at that price. Husqvarna also offers a larger GT size machine with a Vanguard engine and 54" deck for around $3500. I know they aren't quite in the same class as the JD X320 and Kubota T series, but they are also a good bit cheaper and use quality engines.
Another top tier mower to consider if you have a dealer nearby would be a Simplicity Broadmoor/MF 2600/AGCO 1600 series mower (all are Simplicity Broadmoors with different badges). These mowers use Vanguard engines and have Simplicity's Automatic Controlled Traction, which is basically a limited slip. The ACT works well on my MF 2823. Even pulling a weighted 4' aerator uphill in damp conditions, I very rarely have to lock the differential thanks to ACT's effectiveness.
I know the MSRP on the Simplicity is a little on the high side, but in my experience Simplicity dealers will deal on MSRP a bit better than some other brands.