AutoCAD vs. ProEng.
you make an exellent point about taking care to buy the system that is right for you. I would like to expand upon that a bit more. There is more to choosing a cad program than price. Compatability with the rest of your internal systems is important as well. How will you manage the data? How will you keep track of changes that will propagate across multiple files? How will you provide updated prints to your purchasing department? All of these questions must be answered if you are to get a system that works the way you need it to.
I just left a company that chose totally incompatable file management and Solid Modeling softwares. Both were purchased primarily due to cost but niether system would talk to the other. The managers involved refused to admit that they screwed up, so instead massive amounts of time and money were spent to write a homegrown system to duplicate much of the system's functionality. We were originally a ACAD shop, everything was 2D. But more and more of the products were too complex to be adequately visualized in 2d. We spent 6 months evaluating (hands-on I might add) 4 different 3d systems, Mechanical desktop, IDEAS, Pro/E, and Solidworks. PRO/E was our first choice and Solidworks was our second. In that same time period, one of our investors bought the remaining part of the company and we became a wholly owned subsidiary of Halliburton which was running Solidworks. We decided to take our second choice for compatability reasons. Paralell to this. The document management system we were using was unable to keep up and too many people had figured out ways to trick the system into allowing edits without logging them, therefore a new document management system search was begun. Since all of the files up to that point were autocad and the procurement process for the 3d system was still grinding away, the manager who was in charge of it (from IT not engineering I might add) decided to concentrate on managing acad and MSword files ONLY and settled on Lotus Domino..... the result? chaos, lost time, lost productivity, and worst of all broken links between parts, assemblies and drawings.
The bottom line? 3D can save you massive amounts of grief, but only if you specify the system AS A SYSTEM instead of individual parts that may or may not talk to each other.
The point about quality of drawings is a very good one. Autocad is an excellent drafting package, but it is a crappy modeler. most modelers are excellent modelers but crappy drafting packages. If you can put up with less than optimum drawings and really need to visualize 3d assemblies and parts, 3d is the way to go. but if your drawings have to be "just so" to pass muster, then think long and hard before going 3d. The 3d modelers are getting better at doing drawings, but they still have a way to go before they get close to even ACAD R11 in look and precision.