I think most people will agree that crypto wallet on smarthphones should only be used for smaller amounts. So if you stop trading and now you have more then 1000$ worth of coins I would not recommend that you use Mycelium or any other phone wallet. This is just not the correct way how to keep cryptocurrency if you plan to hold it for long time.

However if you have a few hundreds $, and you like to keep coins always in your pocket Mycelium is not bad solution, but you need to prepare yourself to possible problems with synchronization which happen to some users.