I like that it lets me enter my personal information for myself, as well as all of our clients' info at once! It's very easy to use- just input your data into each section you want them in (name/address etc) then go ahead with sending out estimates or invoices; they're right there waiting when finished!! Sometimes takes awhile from entering first time through till actually seeing an invoice but not too long really-- about 1 hour maybe? Not many downsides so far.
Just be prepared if using this program is new territory because some features have been added since we started doing business over two years ago where estimating was done via Excel spreadsheet which made life much easier :) My accountant has used other software before though none quite similar enough like estimateone does what he needs now without any hassle - no more having excel spreadsheets filled up with tons of columns needing formatting every month ;).