One more thing to consider is length of pull. If you are a really tall person, you may find the Type 81 short to shoot comfortably. There is no real way to fix that with the folder, but if you get the solid stock, you can install a modded Zhukov variable length of pull folder, or use a Type 81 to VZ58 adapter with AR Buffer tube adapter.
Accuracy may be helped by getting an optic with the Type 81, but that will require the additional cost of a TI no-drill rail, drilling standard rail, or Murray 3-D's upcoming rail solution. The WK has the rail by default.
The Type 81 has the unbeatable com-bloc reliability. I consider myself an info enthusiast on both the Type 81 and WK platform on this and other forums, and I haven't heard of functional issues with the Type 81 here. There were a small number of rifles bent beyond a certain reasonable measure, but that is immediately apparent, and not a function of hardware dependability.
The WK, on the .556 platform is known for having significant teething problems, including BCGs that disintegrated. That particular issue seems to have been solved as of late, but pistons are still known to be somewhat regularly destroyed, and the screw in charging handle likes to fly away on you or snap. The new shouldered charging handle does somewhat help, as does the SBI enhanced charging handle. You can also get the original non-screw in handle and BCG that can score the side of the charging channel, but otherwise does not cause problems or break. The True North Arms upper has an improved nickel plated BCG, with a screw in charging handle with an indexing dowel that inserts into a matching socket on the BCG. It also has a brass bushing instead of nickel for the piston. The piston problem is likely from the system being over gassed without the stamped and riveted dependability of the the Type 81. This may be an even more pronounced issue with the 7.62x39 mm version of the gun, as the bigger cartridge has more forceful gas exhaust then the .556. The gas block fasteners can loosen with shooting, causing the block to tilt over time and torque the piston, resulting in increasing stress until the piston rod snaps. Thread locking of the gas block is advised to help prevent this. Swapping out the gas block for an adjustable one from TNA (call as they don't currently have a site listing) may help, as you could dial the gas down to the level required to cycle your preferred ammo. If you're going to swap the barrel out for a premium accuracy barrel, you could also get a longer piston rod, either mid from Third Echelon or full rifle length from True North Arms, and that may further reduce stress on the system.
The WK has the advantages of modularity, and can be made more accurate and dependable with the addition of money, but it will never be as dependable as the Type 81. Outside of extensive gunsmithing (like the Grendel barrel swap LMG someone posted a while back), there is no way to easily increase the accuracy of the Type 81 beyond throwing the optic on board, and perhaps removing for-end accessories from the LMG like Murray stated.
One intangible is you are supporting the local Canadian gun manufacturing industry with the WK, whereas you are only supporting a distributor with the Type 81.
It is up to the buyer what of the above factors matter the most to them when choosing between the two firearms. Ideally, one would get both
