Ive been using tthis for about 6 months now, nice and simple to use, invoices and quotes can be modded to suit your company. Stuff it produces looks very smart and proffessional too.
I used Sage for years until I started using this 6 months ago and it is a brilliant bit of kit. Sends you emails to remind you that you have overdue invoices / purchases etc and sends automatic reminders, emails invoices to customers at the touch of a button etc and is totally customisable. Can't reccomend it highly enough.