Much like all of your shops we use Mitchell1 alongside ALLDATA Repair and Diag, and DirectHit. None of them are perfect. I tend to use ProDemand when to quickly shag down codes or groups of them. Likewise, finding an oddball component with the component locator is quick sometimes. ProDemand also links in with the SnapOn scanner in manner for which I have no patience. The integration with the newest SnapOn scanner demo was impressive. Invoices with all Mitchell stuff - (Tracs included are clunky) and not flexible As for customer service they all have ridiculously long long hold times and a "call back" that doesn't.
ALLDATA's Manage Online is the most capable shop management suite by far, easy to access from the cloud and produced the clearest and most professional invoices and the prescans from thier Diag email out very nicely. Manage Online failed us as a NAPA Car Car Center because it would lock up while ordering NAPA parts, randomly order parts for the wrong VIN iteration as it bounced around against the Epicor catalog. So now we are using Tracs - which is Mitchell and all others. If I had to make a choice for a single product suite it would probably not be Mitchell but removing it from our current workflow would leave a big gap. Sadly none integrate well with AUTEL scanners.