Anywhere is fine.
I tried the new Business Class. It's great. Though of a short sector (ie BKK-HKG), the inflight audio/video entertainment is impressive enough to convince me.
The seats are comfortable as well. The J class is split into 2 zones though and I would think that the forward (of the galley) would be slightly more quiet since you're directly behind First Class. Bulkhead is good.
Enjoy!