Don’t be confused and think that a buffer in your signal chain has to always be good. A decent line buffer will not generally color your tone and will help your signal get from your guitar to your amp in a decent manner. But what about what it does besides that?
Think about it this way, a buffer increases the volume of your signal. As your signal goes through the chain, some of it is lost, and if you planned it right, you are at the same volume at the end.
What about things in the chain that are effected by volume, like effects. Most effects will clip if given a too hot signal. Buffers will affect how your effects sound. If you need a buffer, play around with it in different positions in your chain. If it is at the start, will it color your other effects. If it is at the end, will you still suffer from tone loss?
Think about it.