For the case you described, where performance is not a bottleneck, I believe it's all about personal taste.
In thisthis SO discussion, it seems a majority prefers to use the 2nd approach.
I however, am a strong believer of staying consistent. If you use the StringBuilder
class in other classes of your project, stick to using it.
However, When initializing a StringBuilder
, you are going down in performance, so I wouldn't advise to use it for single concatenations. A guideline according to this article is to use a StringBuilder
when four or more string concatenations take place (which is the case in your example.)