How about Apple 7 update 12.2?

Apple 7 update 12.2 experience is average, the network is relatively stable, sometimes there will be some bugs when restarting, but it is still quite smooth and the power consumption is acceptable.

For the old iphone, there are too many kinds of systems at present. The original factory of ios 10 series has never been upgraded, including ios 1 1 series, early 0 and 1 series of ios 12.

Generally speaking, you can choose not to upgrade the updated function, and the utilization rate is low or useless at all. It is best not to upgrade the 10 series, which is a relatively rare version at present.

If you are a telecom user and want to use volte service, you can only choose to upgrade. This time, Apple was very kind and started the volte service.

As long as you update to iOS 12.2, you can use the volte service of Telecom: it can improve the call quality and make phone calls faster while surfing the Internet. If you are a telecom user and want to start this business, you can consider upgrading.

Some new functions under the ios 12.2 system can be upgraded. For example, the ios 10 system of the old iphone 7 has no shortcut keys for data traffic. If you want to try new features, you can consider it.

After upgrading to the new system, the battery life of the old model may decline, the mobile phone may get stuck, and the old model cannot be downgraded back to the original system, so you must know this risk.