My chimney runs right in the middle of our house between our kitchen and dining room, taking up valuable counter space! I'm looking into removing the chimney between the kitchen and second floor, and have been told this is possible with the installation of steel lintels.

Does anyone have any experience with doing this? Removing the entire chimney isn't an option - it would require demolition of a significant portion of our upstairs bathroom.

If this is a brick chimney, please don't consider any option like this. You are presently bearing the chimney weight down through the house to the foundation and by cutting and using lintels, you will be bearing the weight on the house and a massive weight will be point bearing which is worse. Even if you used steel columns to support the remaining chimney, I would be afraid of sudden massive failure. Either leave it or tear it all down. If it is a wood chase with triple wall pipe you may consider this option but it sounds like you have brick.