I use these programs on a Mac OS X platform and for me they are very stable. I have had none of the crashing problems or tech support difficulties that another reviewer of the Adobe Creative Suite has had. For anyone using many design programs at once, enough RAM is always a requirement for smooth operation. But if you have enough RAM and a Mac platform, you should have no significant problems at all. PCs crash more by their nature because their operating system is not as stable as a Mac's, but still Adobe products are not only more intuitive than Microsoft's (for example), they also will crash far less on a PC than most other types of software (like Microsoft's).
Photoshop and Illustrator have always defined the state of the art for photo editing and raster graphic software respectively, and here Adobe is carrying on the tradition. InDesign looks as though it is fast replacing Quark in the publishing industry as well, so if you are a creative professional you will be more than happy in the end to own the Adobe Creative Suite. What else would you use?