IT has nothing to envy from the corresponding electric wheel.
Today I used it for rust scraping and I loved it.
The battery is a huge convenience.
Of course, with four batteries.
I have used it quite a bit as a polisher using its slow speed.
For amateur use, no one needs anything more expensive.

A very good cutting and grinding wheel for both amateur and professional use. I used it to cut both small and large pipes and it cut them perfectly. It has two speeds, slow and fast, and it includes a handle that can be screwed on either right or left, as well as a protective cover for the disc you will use. It also has a key for tightening the disc, always in reverse, by pressing a button on the top to lock and tighten the disc. It is relatively lightweight and easy to operate. Usually, a 4V battery continuously works for about 3/4 of the time, depending on its use and the difficulty of the disc. It is truly worth having in every household or vacation home, especially when you need to quickly and safely cut something without any effort. I hope I helped you, thank you...

Lies, it does not have "Speed Control" but 2 Speeds which change only when it is operating and it does not keep the low Speed but always starts with the High Speed.
The Speed Change button is so small that if you have gloves it is difficult to press in an inconvenient spot.
Instead of having the Switch on the thumb while holding the wheel, it is placed on top. It's a shame because the Cordless Drill Driver is worth it and has good batteries.

It cuts construction iron easily and generally I had no problem with any iron. And for wood sanding very good, about 20 minutes of continuous use with a 4Ah battery. For the use I want, I have never needed the slow speed, possibly good for polishing (?)

I have been using it professionally for quite some time, I have also lent it to others, it did not present any problem with the 5ah battery, it is very good.

Very convenient and practical. With a 4Ah battery, you can cut a lot. Just don't push it like a mains power tool because it stops. It has a 2-speed selector. All speeds and half. It doesn't vibrate and even after a while, your hand doesn't feel heavy or numb.

Very good wheel, I suggest you open it and fill it with grease because there is no grease at all on the gears. There is a relevant video on YouTube https://youtu.be/1NQurPL7-cw