Depends what you're after
Really depends on what you're looking for. If you're looking for long term ownership of a car to tinker with on winter nights and drive very occasionally in summer, don't mind waiting weeks for parts and spending more £££ on maintenance than on tyres, taxes and fuel then these are the cars for you.
If you want something to drive every weekend when weather allows, put on a reasonable mileage, including some tours to Europe or around Scotland, have an easy time with servicing and freely available parts then sell easily after a couple of years when the itch returns then these are not the best cars.
I've never been a TVR fan. Several friends have had love/hate relationships with the marque, loving them when they run but recognizing they will also try to kill you at some point during every journey. Maybe that's their charm?