I use Grasshopper with my cell phone account, the two merge easily. Grasshopper gives small business like mine an economical way to have a toll free number with all the options of a large corporate phone system.
Great service, great price,
A little difficult getting the voicemail functions set up. The recording part is easy but if you're using it in conjuction with another phone system it can be tricky to use the extension functions and get the voicemail messaging right.
The other options I considered were more of the usual large carrier variety. I chose Grasshopper for the price, ease of use and customer guarantees.
I use the Toll free capacity
Ease of having a back up number
My business is young yet, I am not yet showing a profit.
I would consider switching to Grasshopper for all my needs. I started low, and have adjusted as needed.