I have used the MM for a long time now. I am on my 2nd one now as i lost my first one (don't ask!).
I use mine with an app called xDrip+ which is much prefer over other programs, however I have never used Glimp so cannot comment on how good that is. The Tomato app from MiaoMiao itself is not worth bothering with in my opinion, but feel free to find out for yourself.
Your choice of mobile phone is important. I have an Android phone running Android v9 and i often have to reset my xDrip+ program throughout the day because it has lost its BlueTooth connection to the MM. I am fairly certain that this is a problem with my phone and not the MM however, because most other people do not have this problem.
When i first started using the MM I had issues with the adhesive tapes that come with it. They left red welts on my arm after about a week. I have since found out that just about every type of adhesive leaves welts on my skin apart from the adhesive used on the FreeStyle Libre itself (thank god). So again, do not see this as a common problem.
Also, when using adhesive, i found that after about a week, there was a bit of a smell coming from my arm. This was my arm sweating under the MM. I also had to clean the MM off thoroughly every time i changed it, to get rid of the smell.
Because of the adhesive/smell issues i invested in an MM Holder and arm band. I bought several different ones until i found one i liked. I bought one from Pimp my Diabetes and another from a company called Shapeways. They are usually made using 3D printers and come in lots of different styles and colours. I lost my first one because i chose one that did not use an elasticated belt. I got jostled about in a crowd and it must have fell off. Now i only choose ones that come with an elasticated belt.
Now i don't have to worry about adhesive issues any more and because i can take off my MM before having a shower, i can keep the area around my Libre nice and clean. I also do not have to worry about spending so much time cleaning my MM, because it does not use adhesive any more. A wipe down with a soapy cloth is enough, then thoroughly dry it. Some people wear their MM in the shower, but if you are using an armband, then you have to consider that the elastic band will get wet. It is not nice to wear a wet armband for any period of time.
I hope that all this helps you.
I would never be without my Libre/MM/xDrip+ setup now. It helps me hugely.
Good Luck