Advice needed - Looking to buy a DI press. Your help needed.

[starprintingltd]

Hoping someone can give us advice on buying a DI Press.
We already run a Ryobi 524H and looking to buy a DI press for quick turnaround etc...
We have seen some Heidelberg QM46-4 DI going at good prices.
We don't know nothing about them and need your help,

1. Are these machines reliable?
2. Is 15,000 Run Length work and turn suitable for the press.
3. What are the common problems?
4. What do I need to look at when buying this specific DI?
5. Are they expensive to run?
6. Can litho paper be used for these presses.
7. Any other machines going at the rate these do?

We really need all your advice as possible and will appreciate it.
Thank you/