My new TT-50 (2019 model) arrived today. I used it to true up my SG-250.
When I review a Tormek product, Most fall into my category of "recommended for new purchase, but no need to replace the previous model if you already have one". A few products, most notably the SVD-186 gouge jig, I rate highly enough to recommend purchasing it even if you are already happily using the predecessor product. I include the new TT-50 2019 model in the recommended for new purchase category. If you are presently using the original ADV-50 truing tool, I recommend replacing it with the latest TT-50.
I am impressed with its design and quality of machining. Like most new Tormek jigs, it utilizes machined zinc. With the older version of the TT-50, some users were experiencing bounce. Ionut solved this problem by using two small electrical ties. Recently, Sharpco showed using a strong magnet to solve the bounce problem. I have never had the bounce problem. If I did, I would try one of these two fixes.
The redesigned TT-50 is priced the same as the older TT-50, $93US. It is essential. It should be among the first purchases for every T4 owner.
My usage recommendation is less aggressive than the included Tormek instructions. I favor very light passes, perhaps only half a microadjust number, especially when starting out. I also favor frequent truing. We paid for a Tormek, why not optimize it with a true wheel. True often and lightly.
Ken