It is very easy to update and and delete data in Salesforce using this tool. Some of the features that I think are particularly helpful are: uploads and updates using Excel, using constants when uploading data, updating data using business logic, identifying and performing deduplication, and insight into error records.
When uploading new records, you can specify a constant for any of the fields. So if you know all of the uploaded data is a certain record type or is owned by a particular user, you don't have to update your spreadsheet. You can just use constants. Using constants and saving scenarios is a great way to improve efficiency.
If you have the need to replace one value with another, this tool can do. For example if we run out of stock on a product, we can upload Opportunities with a different product to replace it within minutes.
The de-dupe has many options for matching and you can build your own. You can peruse through the dupes and determine if you like the algorithm and then use it to automatically dedupe those records. There are some options to determine the master and rules for when the master has blank fields but the dupe has valid data. I like the ability to add a weighted score to the rules to ensure you can handle complex scenarios.
Finally when records error out, Demand Tools creates a file that you can use to determine the error, correct it and reload. This is incredibly useful when you run into resource limitations.
Good, solid tools.
My favorite tool is Mass impact. It allows you to update records based on logic only. No file uploads necessary! This is extremely powerful for mass updating records. I've used it to update relationships, correct older data, and update values during migrations.
There has been a great upgrade to allow searching for tables.
I've noticed recently that I run into fewer resource constraints. Salesforce can be tricky when there are triggers involved. Demand Tools gives you options to use the batch API and to easily control the size of the batches. Even if I have to update thousands of records at 5 at a time, I can leave this chugging away in the background and know that I will get a full accounting of everything that processed. Review collected by and hosted on G2.com.