I owned an '85 LeMans MkIV for about 5 years and loved it, despite consensus saying it was the least desirable of MkI through V. My own ranking of the others (based on a mix of subjective factors) would go - MkI, MkIII, 1000s, MkV, Mk II.
I took it on the track, commuted every day, filled the panniers with shopping, toured up and down the east coast of Australia 1 and 2 up ... put about 50,000km on it ... and did my own basic servicing.
Styling - you will just need to form a view. In mine, none past the MkI are oil paintings. But I'm not offended by any of them ... quirky is all.
That dreaded 16" front wheel - they certainly handle differently to their 18" kin. Here in Australia there was a lot of bollocks written about them and their poor handling, but I found that not to be the case provided you recognise the differences and ride accordingly. The steering is quicker but the wheelbase stays long. They prefer smoother roads. They are more sensitive to tyre pressure and wear profile than 18" guzzis, but if you manage that they handle just fine. I also upgraded the front suspension units (they were due). In terms of riding style I found the trick is to steer with the pegs & seat rather than wrestle the bars ... just let the front wheel do its own thing.
Collectability - I would agree its at the low end ... way below a MkI, but let's face it guys, it better than a Lario!
Hence, value for money is high.
Good luck!
Jonathan