Which one is more suitable for you (or easier to use) depends on a lot of factors, like Rath said. For me, it was important that the software would run efficiently and quickly, which is one thing C can just do better than Go at the moment. On the other hand, I'm missing out on Zap for example, which is a bit of a pity, because I don't think there are similar clients that allow you to kind of use your node from other machines for day-to-day transactions. Well, maybe through RTL, but it's not really focused towards that; instead more on maintaining and administering the node. In general, it seems there is more software support for LND. Another example would be BlueWallet, which allows to connect only to LND instances (through LNDHub).

You don't have to, but always installing new stuff without removing the old one, in the long run just clutters your machine.