The changes in Azure SQL DW Compute Optimized Gen2 tier are:
5x query performance via a adaptive caching technology. which takes a blended approach of using remote storage in combination with a fast SSD cache layer (using NVMes) that places data next to compute based on user access patterns and frequency
Significant improvement in serving concurrent queries (32 to 128 queries/cluster)
Removes limits on columnar data volume to enable unlimited columnar data volume
5 times higher computing power compared to the current generation by leveraging the latest hardware innovations that Azure offers via additional Service Level Objectives (DW7500c, DW10000c, DW15000c and DW30000c)
Added Transparent Data Encryption with customer-managed keys
Those are some good improvements. #2 in particular makes it possible for Azure SQL DW to be useful in a much larger number of environments.