Instruction: Extract information from the supporting document to answer the given question.

Input:
Question: Can you long simmer for 6-8 hours using a cast iron dutch oven on top to take the place of a crock pot?
Document: Sometimes the squeal was very loud. I read in a blog that it could happen because the Circulan emblem on the bottom center of every pot and pan is recessed, therefore not making direct contact with the surface.4. When using my cast iron dutch oven, no squeal, not even the clicking I normally hear with the other pans.5. Tried an experiment tonight with the cast iron pot, Circulan and Update (bought from a commercial chef's warehouse).
It is light weight and very portable. Easy to use and cooks fast. You can use it with a cast Iron dutch oven and make a great slow cooker that you can actually brown the meat first. After you brown the meat and get everything up to temp you turn it down the temp, set the timer and walk away. I also use it to make Beer it boils 6 gallons of water faster than my stove. It was a great help at Thanksgiving.
I found that 3-4 was sufficient for most of my needs. I hiked it higher to bring to boil, then reduced to keep it at a boil.Where to place this cooktop:  The cooktop itself sits 2-3 inches above the countertop. Placement near an outlet is obviously important, but if you plan to use this with a stock pot or Dutch oven the upper cabinets might be in the way.
I use this cooktop with my cast iron dutch oven. It works well on the lanai for deep frying to keep the grease outdoors. It contains a fan that makes a little noise that is unnoticed outdoors. When preparing large meals it frees up needed space on the kitchen stovetop. It is very useful.
I was so excited to get this product. And to be honest, it worked great until it didn't! I got about 5 uses out of it before the unit stopped working. I think it short circuited or something and now every time I turn it on, I get an EO reading on the dial (I assume that's an error message) and the unit does not work... It worked great with my Cast Iron Skillet Dutch Oven but why did I pay so much for 5 uses?!!!
(And require 220V which may be a problem in many households. )This is also our 2nd Max Burton induction cooktop. The first started malfunctioning after 4 months (The button which increases power/temperature settings stopped working.) Even though they did not have to Amazon replaced it immediately. Kudo's to them.We have found that our 'old fashioned' cast iron frypans and dutch oven are, by far, the best cooking vessels. I bought most of these while in the Army as various PX's many years ago.
I got this unit for doing some hobby craft work- basically I use it to boil water most of the time.It was larger than I expected, which was a pleasant surprise. I use a large enameled cast iron pot and it fits great.I love that it has the "temperature hold" feature. I can set it to keep water just below a simmer and it works a treat.
Just ordered and received my new cooktop. All I can say is why did I wait so long. Got the recommend from a fellow blogger. Since we live in a tiny house I don't have a stove right now. I use a micro wave, toaster oven ( the biggest one I could find, and a two burner electric stove top. This induction cook top is the greatest. It took only two or three minutes to get my water in my tea pot to steam for my ice tea.
The actual heated area is quite small (about 6"). If you use cast iron pans it spreads the heat quite well though.It is great for heating foods quickly. I had a can of baked beans heated in about 2-3 minutes.The glass surface is very easy to keep clean. It does not bake food on.I found the power levels hard to work with. Level 3 would boil over my pot of water. Level 2 would only boil part of the time.
I love this cooktop. It is amazing. I hardly ever use my range cooktop anymore. I wish I had bought an induction cooktop instead of my Bosch range. When I go to fry my egg in the morning it takes less than a minute for the pan to reach cooking temperature. My Bosch glass top range takes 5 to 6 minutes to heat my cast iron pan to the same temperature.
Answer: I would not recommend cast iron.  Too easy to scratch the burner plate.