+ has problems as string concatenation, but that doesn't make & a good choice. We still use a lot of C-ism's because people are used to them, and any deviations from C-like behavior, which at this point could be called "common behavior" just increases the learning curve and the cost of a context switch.
Personally, I like Perl's period(.) for string concatenation, but I think it can too easily get lost in the line, especially for more complex stuff.
Period has a general meaning of ending a sentence. At this point in our history, people willing to clear the deck of C-ism should be encouraged. I think the learning curve is worse when folks imitate C for no reason other than computer tradition as opposed to building something that feels tied together. We ditched a lot of older habits with C, we should continue the path.
Personally, I like Perl's period(.) for string concatenation, but I think it can too easily get lost in the line, especially for more complex stuff.