Exactly. I've used everything CS3 and up, and maybe I don't know how to use them well enough, but they seem like the same thing.
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I don't use many of these features, but that doesn't mean they are not being added. Many of the new featyres I DO use a lot.
CS4 features smoother panning and zooming, allowing faster image editing at a high magnification. The interface is more simplified with its tab-based interface[51] making it cleaner to work with. Photoshop CS4 features a new 3D engine allowing the conversion of gradient maps to 3D objects, adding depth to layers and text, and getting print-quality output with the new ray-tracing rendering engine. It supports common 3D formats; the new Adjustment and Mask Panels; Content-aware scaling (seam carving[52]); Fluid Canvas Rotation and File display options.[53] The Content-aware scaling allows users to intelligently size and scale images,[51] and the Canvas Rotation tool makes it easier to rotate and edit images from any angle.[51]
Adobe released Photoshop CS4 Extended, which has the features of Adobe Photoshop CS4, plus capabilities for scientific imaging, 3D, motion graphics,[51] accurate image analysis[51] and high-end film and video users. The faster 3D engine allows users to paint directly on 3D models, wrap 2D images around 3D shapes and animate 3D objects.[51] As the successor to Photoshop CS3, Photoshop CS4 is the first x64 edition of Photoshop on consumer computers for Windows.[54] The color correction tool has also been improved significantly.[51]CS5 introduces new tools such as the Content-Aware Fill, Refine Edge, Mixer Brush, Bristle Tips and Puppet Warp.[58] The community also had a hand in the additions made to CS5 as 30 new features and improvements were included by request.[58] These include automatic image straightening, the Rule-of-Thirds cropping tool, color pickup and saving an 16-bit image as a JPEG.[58] Another feature includes the Adobe Mini Bridge which allows for efficient file browsing and management.[58]
CS5 Extended includes everything in CS5 plus features in 3D and video editing. A new materials library was added, providing more options such as Chrome, Glass, and Cork.[58] The new Shadow Catcher tool can be used to further enhance 3D objects.[58] For motion graphics, the tools can be applied to over more than one frame in a video sequence
Adobe Photoshop CS6 brought a suite of tools for video editing. Color and exposure adjustments, as well as layers, are among a few things that are featured in this new editor. Upon completion of editing, the user is presented with a handful of options of exporting into a few popular formats.[62]
CS6 brings the "straighten" tool to Photoshop, where a user simply draws a line anywhere on an image, and the canvas will reorient itself so that the line drawn becomes horizontal, and adjusts the media accordingly. This was created with the intention that users will draw a line parallel to a plane in the image, and reorient the image to that plane to more easily achieve certain perspectives.[62]
CS6 allows background saving, which means that while another document is compiling and archiving itself, it is possible to simultaneously edit an image.[62] CS6 also features a customizable auto-save feature, preventing any work from being lost.[62]
So CS 6 added the least in terms of features, but did significantly enhance workflow.
As for pricing. I would be an every other version update except I am on CC right now and have been for almost a year. For the educational users it is cheaper that way all the way out to 6 years or so (assuming Adobe doesn't raise the price, but then they might have raised the price of their stand alone licenses anyway). For others, the pricing is far worse. I'll reevaluate every year and if good enough cheaper options appear, will go with those.
I understand the disappointment of many on here, but not the anger. Adobe doesn't owe you anything.