I have also used both R.O.Writer, Manager, and Protractor a bit. Mitchell Enterprise is licensed Protractor from Canada, and very strong for multi shop locations and different levels of work stations.
Take a look at Manager SE or Manager Plus SE (Inventory). I believe they are on 6.4 now. It has some additional features and easy catalog integrations. It's more robust with new features over regular 5.9 manager. Protractor is nice, but pricey and a bit too windows explorer layout fo me.
http://www.m1products.net/sms/managerse/upgrade.asp
http://www.seupgrade.com/
What's new in Manager/ManagerPlus SE 6.4
Microsoft Windows® 7 and 64-bit operating system compatibility.
SQL database allowing wireless connectivity.
In addition to all the online parts catalogs available in Manager 5.9, Manager/ManagerPlus SE also integrates with many new catalogs including CARQUEST WebLink v2, Autoi (often used by Federated Auto Parts), and the MORE catalog for ordering factory dealership parts.
VIN decoding through CARFAX.
Integrated credit card processing.
Quick access buttons to tab between Management system and OnDemand5.com / ShopKey5.com.
Integrated e-mail function for easy e-mailing of estimates, repair orders, and invoices to customers.
Custom Shop logo printed on estimates, repair orders, and invoices.
WIP (Work in Progress) - Columns are easily sortable, searchable, and can be dragged and dropped into place.
WIP (Work in Progress) Individual cells can be edited on the fly.
User definable vehicle notes categories.
Repair Order locking to prevent two users from editing the same record at the same time.
Online Help system and Training Videos.
Installation and lease license extension performed via internet.