When HotT was first broadcast, I recorded it from the radio. Now, all these years later, I finally get the chance to listen to it without interference.
I remember listening to it and chuckling most of the way through, laughing out loud at some of the antics of Crown Prince Vegenin and Agar son of Athar. The acting (or, rather, overacting) by the strong cast (Paul Eddington, Frank Middlemass, Simon Callow, etc.) is great tongue-in-cheek stuff. Patrick McGee's 'narration' is nonsense, and the better for it.
Listening to these CDs, I am reminded why I found it so funny, though, with my adult sense of humour, I didn't find it quite as sidesplitting as I did when I was 18.
Yes, it is silly at times. Yes, many of the names are jokey parodies from a bygone era (the 80s) and have no meaning to many listeners nowadays. Yes, there is still much to chuckle at.
It isn't a gagathon in the style of Bored of the Rings, but that was never its intention.
I would say that HotT is reminiscent of early Terry Pratchett books - laugh out loud funny when they came out but still humourous on subsequent reading.
For the sake of a few pounds HotT was a good purchase. It isn't going to make you wet yourself but is a at least as funny as a modern series such as Elfquest.