Being an ex user of QuickBooks Payroll (which I wouldn't recommend, despite loving QuickBooks) - I use Moneysoft Payroll Manager.
I find it very easy to use, very competitively priced with the unlimited payrolls package. The reports are nicely laid out, informative and easy to understand that even your clients can understand them.
The support telephone line has always answered within a few rings, and my queries have been sorted quickly and efficiently by the person that answers the phone - so I'd describe their support as exceptional.
The Auto Enrolment facilities appear to be comprehensive, along with the written support pages for this subject, though I haven't actually staged with my first one yet (only 2 months to go) so can't really state what this is like.
I have even put 3 of my clients onto the package that wanted to do their own payroll, but with me just overseeing them when they have problems, and all 3 love it and have said it's so much easier to work with and clearer than Basic Tools from HMRC - though I guess that isn't that hard to achieve!