Thanks for your thoughts everyone, it has been interesting to read people's experiences.
Here's my threepence worth. If you want to do predominantly imaging, whilst at the high end ($$$$) there are very good alternatives such as RC scopes, even on a modest budget it is possible today to acquire really high quality raw data (that of course nobody bothers to process
) using relatively affordable, but necessarily 'small' refractors. Many have chosen this path with great success and I'm not knocking it. After all, we only do astronomy because we enjoy it and how you achieve that is up to you.
As mentioned in my initial post though yes my APM 152mm yielded what I think is a superior view of Saturn than the 16" SDM, if visual is your thing it is a great deal of money to spend for superior view of just 4 objects, the moon Saturn, Jupiter and Mars. Mind you, that makes it three times more useful than a solar scope
.
My APM 152mm today would set up back just over AU $14k for the OTA and rings (and for half a million dollars APM will make you a 20" APO) but for that kind of money you could have a 20" skywatcher dob or a slightly smaller elite-maker dob, like Obsession or SDM. I reckon it would be worth sacrificing the views of the bright solar system objects to open the door to the entire Messier and NGC catalogues. In short, an APO refractor is worth it for imaging but is poor value for money when it comes to visual - and that's coming from someone who loves refractors!
I would therefore be recommending a beginner who wants to start with visual at least to buy a dob. A small refractor will prove disappointing and may fail to inspire.
Chris