FYI: I don't believe ISE is using the same quality metal causing these newer models to rust out quicker but, in my recent experience, I found that people who use their disposer properly will get at least 5 years service...that is acceptable for my purposes in the apartments. I did have 2 ISE disposers that only lasted about 2 years. One was from a tenant who almost never used it and allowed it to rust extensively and corrode from non-use. Using it helps keep it clean too. The second one, I determined was not being used properly, i.e., the tenant was not running water before turning on disposer causing food debris to accumulate in the small chamber below the blades/masticator.

Update: As an aside, I also learned from my research that the best way to clean my disposal is to use citric acid. Having previously had no idea what citric acid was used for, I decided to order some from Amazon, going with the brand my sister uses: Citric Acid Powder - Ultra Fine Pure Powdered Crystals - Natural Preservative Food Grade Quality (16 oz) and gave it a whirl after 3 months of using my disposal. I let the citric acid sit with some water in the disposal for about ten minutes, and then I let it run for a solid 2 minutes. I repeated the procedure a few times and after about 30 minutes—wow, all the leftover gunk and food was flushed out of the disposal, leaving it clean with a very mild citrus scent. I feel like I’m becoming a real DIY at home kind of guy.

Keep anything too hard out of the disposal. The shredder will dull and become less efficient. Small hard objects can also get stuck and jam the rotating parts. Each garbage disposal has its own capacity for hard objects. The more expensive models of the same brand tend to have higher hardness capacities. The instruction manual usually specifies a list of objects to avoid. You can also gain experience with your own garbage disposal. Strong vegetable fibres can jam some garbage disposals, as well. If something may be harder than what the disposal handles, just put it in your trash can or think about setting up a worm composting bin. Some items to avoid are:
If your garbage disposal is making a clicking or rattling sound, there may be some food particles that will not grind up inside. Remove power from disposer, reach into the sink hole with a pair of tongs and remove anything that is still down in the disposer. Test your disposer to be sure the noise is gone. If not continue troubleshooting your disposer issue (see below).

Garbage Disposal Replacement