My company was previously on Salesforce and recently switched to Sugar, so I'm seeing everything through that lens.
I was baffled to learn today that you cannot do a mass update of existing contact records using email address as a sync point. This is a very common need for us. I realize that there may be duplicates in the system, but the import should flag dupes and allow you to pick which record you want to update.
I dug into the documentation to try and find a solution and I was a tad mortified to discover Sugar's suggested workaround: using VLOOKUP in Excel to populate the record ID into the spreadsheet prior to upload.
This seems insane to me. Rather than building this capability into the platform, they are suggesting a user keep an entire copy of their Sugar data set on their local machine. That's a MASSIVE security risk. Plus, if you have a large data set, the average business PC is going to struggle mightily with processing this type of function.
Somebody please tell me there is another way.