Glad you asked as I have a big Mitz LT-30 and a PL-L1000.
The big Mitz is uniquely solidly built for a Japanese LT (or any TT), sounds right neutral and precise, and works flawlessly once sorted out. It's not particularly finicky about being absolutely level, the big Pioneer is, very.
The Pioneer LT is less substantially made and more "lively" and rich in resonance potential, the arm carriage rails MUST be absolutey level for it to work correctly. It's ergonomics with the shuttle knob are delightfully first rate and the unique linear motor arm transport functions faultless and responsive if the levelling is right and the rails are kept clean. The only thing that goes wrong is the cueing belt and the cueing motor's resilient mount shroud deteriorates. Easily dealt with and not a show-stopper. The robotics can handle 45s and all 3 microgroove record diameters with manual touch-button switch-over. I cannot comment on sound as I use mine for strain gauge carts exclusively but I'd guess it's less neutral than the Mitz, depending on the cart choice. I got the Mitz mainly for MC carts for which it seems to be well-suited with it's nearly 3 lb carriage mass tho' it should do fine with most carts. The Mitz is automute, the PL-L1000 not. The PL-L1000A is automute but lacks the shuttle knob and the lesser for that change IMO. Both Pioneer LTs have a suspension isolated base, the Big Mitz not. The Pioneer LTs do not have record sensing, the Mitz does and need be defeated for transparent/translucent records.
If I had to rank them to own both I'd use the big Pioneer for my "preview"/casual player with a nice cart with an assortment of replacement stylii and the Big Mitz for critical/ deep pleasure listening with one or more "serious" MC carts.
