We used Estimate for 2 years. We used signVOX for 2 years and have been using shopVOX for over a year now. I truly believe when used properly it will increase your profit margin as well as your productivity. We used several system and methods giving each a 6-8 month trial. ShopVOX by far exceeds the other we used.
With that being said, it also still lacks in several areas for us. I don't believe there is a system out there which is the best for everyone.
For example: We manually put information in Quickbooks and use it for accounting. I don't like how shopVOX transfers information to Quickbooks. We use shared Google calendars for tasks to be done. It is much more user friendly than shopVOX and allows quick rescheduling of events. ShopVOX is used to control most everything else.
Where I believe shopVOX really shines is total control of pricing. It allows anyone in our shop to accurately quote and price everyday jobs (banners, panel signs, vehicle graphics, store front graphics) within minutes. Everyone in the shop can also see where each job is in the workflow. If a customer calls to check status of a job, whoever answers the phone can advise the customer without asking anyone.
On a side note, we use Ringcentral for our phone system and really like it. They recently purchased Glip.com and it is offered as a free service to customers. I am thinking of switching from Google calendars to Glip for task scheduling.
If anyone finds the business management unicorn that works the best for everything, let me know.