i had a brief flirtation with the skybook software after the voucher that appeared for a trial period.
It works well enough, just did not provide me with the one stop shop I really need. 80% of my flying is IFR and half of that is IFR with a transition to VFR to land so I need something that covers both camps.
To correct IO540 post if you want IAP plate viewing in Flitestar you have to have Jeppview installed even if you don't use it. And contrary to his experiance I found that 98% of the autorouting trips it plans pass straight through the CFMU without problem. You have to learn to be a bit cute for some routes. I went to Brest the other day and FS routed me airways around the Jersey Zone, a quick edit of the flight plan to include ORTAC and JSY gave me 140nm shorter routing which was accepted. Its a good bit of software but you really do have to understand how it works.
I work with software all the time so it's easy for me.