How is Onshape different from other "cloud" CAD products?
There are other mechanical CAD systems that are “semi-cloud.” They are traditional desktop-installed software programs that are downloaded from the cloud and store files in the cloud, etc. They require locking and copying disk files for collaboration. (In other words, they are still fundamentally file-based desktop applications.)
While these cloud extensions to traditional file-based CAD are useful, they do not provide the benefits (see “What is Onshape” above) of a cloud-native application such as Onshape. In fact, because Onshape is architected specifically for the cloud and is not file-based, many of the “features” of traditional PDM “add-ons” are either built into Onshape, or not required at all when using Onshape.