Despite the name, the Alzheimer's Society covers all types of dementia so it's worth contacting them too.
My dad had Parkinson's dementia, which is under the same diagnostic umbrella. There's a lot of common ground in symptoms, but there were also of course the specific Parkinson's symptoms so not a complete overlap with the other Lewy body type.
He had virtually no memory loss of the type people think of as a feature of dementia. He always knew where and when he was, who people were, their names etc. He lost some procedural and executive memory - things like making a phone call became increasingly difficult.
His most obvious symptom was delirium (particularly the idea that all the hospital or care home staff had been replaced by imposters). This could happen at any time, but was particularly common during sundowning. It generally didn't last more than a few hours and sometimes much less. Afterwards he could remember the experience but also mostly recognise it wasn't real. On the whole the more outlandish the delusion, the more likely he was to recognise it as a cognitive glitch; more plausible ones he tended to hang onto as having been real.
And to some extent he lost a sense of time and practicality - if he wanted something he wanted it right that moment, and had difficulty comprehending that I couldn't instantly achieve it when I was 3-hour journey away and at the mercy of airline schedules. This was mainly linked to delirium-related wants, but not exclusively - and may have been a feature of the Parkinson's rather than the dementia side, because that's known to mess with people's sense of time.