Are you using these for ham or LMR? They are NLA, so I can't comment on how long they will have support from Vertex.
The TK-7/8180 are comparable, and are still currently manufactured. They can be found cheap if one takes their time and be patient.
The Kenwoods have a superior display(14 character dot matrix) 512ch/128 zones. Both have comparable features like MDC/2-tone ect. The Kenwoods have really decent scan options as well. Having used a couple different vertex mobiles at work, I can say the latest Kenwood mics feel much more solid than the Vertex mic.
Not sure if it is important but the Kenwood supports 400-470MHz and 450-520MHz, it appears the Vertex only supports 450-512MHz