I have owned a Hallmark boat from new in 1998; a 45' cruiser stern. I was lucky to get the boat as they went bust soon after.
It has served me well for 20 years. I had it surveyed in 2014 and the sides and baseplate are wearing well, with minimal pitting/corrosion. The shell was made by a Peterborough fabricator (cant remember the name).
The fitout was cheap and cheerful, and over the years we've altered and improved a lot of things. The engine is reliable (Sole/Mitsubishi 3 cyl).
It has been probably the best thing I've ever bought, and would sell now for more than I paid. There's a lot of snobbery about these boats but they introduced lots of people like me to the canals. I've never felt the need to buy a bigger or better boat.
Having said that the price of the OP's boat is a joke!