I have been training on one since January and its a great piece of equipment. I highly recommend it. Have dropped 40 pounds and my body fat has gone from the mid 20’s to the low teens.
I love the ability to quickly move on to another exercise or super-set, and there pretty much isn’t anything you can’t do/train on it. The only thing I would say is to get the additional weight bar for squats. I was quickly able to reach the top setting (6) doing single leg squats on it.
I have been training my clients on a Total Gym for years and absolutely love it. I upgraded a few years ago to the Power Tower (which I call Total Gym on steroids).
It is very versatile and great for all clients. You can also buy a package for Pilates attachments. It’s not a reformer but it can emulate most functions pretty well.
I have been training clients on a Power Tower for about 3 years. As Karin mentions, it’s a versatile piece of equipment, readily adaptable for a variety of clients. If your budget allows, you may want to consider the Power Tower since you plan to train clients. The Power Tower is considered a commercial grade piece of equipment, it will be more durable and functionally easier to use. Since the Total Gym XLS is designed for home use, the warranty may be voided if used in a commercial setting (for training clients,i.e. business use). Good Luck!