MuggyDude and I can answer this one! In fact I already have in another thread, but I don't know where that thread is so I'll just do it again.

Remember that I fly my MCX with a CX2 transmitter. The CX2 transmitter is not anything special, but it is very conventional in design and size. It's a $50 piece brand new. I have not flown the MCX with a stock MCX transmitter other than one test hover in the local hobby shop. Since I got this MCX for training, I want my transmitter to be as 'typical' as possible.

That said, I can't imagine how any helicopter could have better defined control than the MCX. I believe that is is about as good as it gets for an indoor helicopter. Fight speed is less than walking speed until you make modifications to it, but that's OK indoors. Unlike the CX, you can fly around furniture and lamps and land on knick-knacks without worrying about damaging either your wife's stuff or the MCX. Slow flight is great for learning orientation.

Because the MCX is about a 1/8 scale CX, the area where you fly is effectively 8 times larger. I need more room for flight than an 8 foot ceiling with furniture and a ceiling fan. I was constantly hitting stuff with the CX. The CX moves far more air so you have a significant breeze after just a minute of flight before it becomes slightly unsettled. Because the CX moves a good bit of air, when you get near a wall, you'll hit the wall. Fly near a chair, you hit the chair. They hate to fly through doorways. Air currents again. The MCX has very little trouble with any of these issues. I practice tight patterns over the dining room table. It's just the right size area.

So I guess it depends on your flight area. A friend has a horse farm and he flies in the riding barn. Another is a teacher and he flies in the gym. Some have access to a gym attached to a church and they start or join a flying group there. If that's your deal, get the CX2 or CX3.
If you want to fly in the house, get the MCX. If you have a large open room with a high ceiling, it's your call. I'd go with the MCX. And if you want to get something larger, there will be a good market for the helicopter used. You really can't lose.