UPDATE: added seat pictures for the person who asked if the seat could be swapped out.ORIGINAL REVIEW:This is exactly the bike I wanted. I had an evaluation session with a personal trainer, and all I was doing at the time was running for exercise. She told me I needed to mix things up and try doing a spinning class at least once a week. In my previous job, I was able to go to a spinning class at the gym at 11 a.m. once per week. Then I started a new job and couldn't do that anymore, so I wanted to get a spinning bike for home.The first bike I had at home was recommended by my spinning class instructor. It was a LeMond Revmaster. It was very sturdy and worked great. What I missed were the metrics I got from the bike computers on the spinning bikes at the gym, specifically the indication of power output in watts. The LeMond had a simple twist-dial resistance mechanism that wasn't calibrated, so I couldn't consistently set it to a given power output, and it tended to squeak and make it untenable for anyone else to be in the basement when I was riding the bike. So I started looking for a new bike.The first bike I bought was another big-name brand that starts with Nor and ends in track. It was a total lemon. It was unstable and wobbly. It had no fly-wheel weight, so you couldn't comfortably stand up and pedal. Although it indicated power output in watts, it wouldn't show you a GRAPH of power output or offer any workouts based on power output. Their app with iFit was fundamentally flawed in that the graphs and workouts were all based on "speed" from RPM, which is artificial and doesn't take into account resistance and how hard you were working. Their app was unstable and crashed frequently, and they wanted you to sign up for their monthly subscription service like the other big-name internet-connected spinning bike that begins with Pel and ends in Ton. It took a lot of time and effort, but I finally got that company to take back their wobbly piece of junk and give me a refund.So I started shopping around again. The Keiser looked strange to me in the pictures on the internet. I thought it would be wobbly. I found a local gym that had the Keiser, and I went and asked them if I could just check it out. It seemed pretty sturdy to me, so I bought one.Thanks to the other reviews here on Amazon, I did NOT pay for the "expert assembly" and I assembled it myself. As it turns out, I had most of the tools already. I only needed the crows feet, which were a pain to get the two specific sizes they needed. Assembly was pretty simple. The directions are well-written. Other people here have posted here that Keiser has a good video to help with assembly, too, but I didn't need the video.I've used the Keiser M3i bike (UPDATED 11/1/2020) SEVERAL days per week for over a year now, and I like it A LOT. It's leaps and bounds better than the previous lemon I bought.+ It's very solid and sturdy. It doesn't wobble at all.+ It has a good size weighted fly-wheel, so you can stand-up and pedal.+ It has magnetic resistance and barely makes a whisper of noise.+ The resistance control is very simple and calibrated to show you a number of what "gear" you're in on the display.+ The display shows you your RPM, Power output in Watts, Heartrate (using Polar HRM), "gear" (resistance setting), calories burned, and distance.+ The app on my phone shows me a graph of my power and heartrate vesus time and keeps a record of my work stats.-- Minor downside: They don't automatically sync up the data with MapMyFitness, but they DO export the data in TCX file format, which you can manually import to MapMyFitness. I can see all my workout stats on MapMyFitness from downloading the TCX file.Overall, I'm VERY pleased with this Keiser bike. This was money well spent.