Make a tragic fiend-spec if all you want to do is rely on fiend to kill with. It's a perfectly valid and very effective way to rack up kills.

Romantic is the only repertoire I've played to 51, but I did have a lot of hero bards in my range to compare and contrast with. Generally, I found that with edges and a level 51 instrument, all of my songs were pretty effective. My damage songs weren't amazing, but they didn't seem "weak" by any means. My fiends weren't amazing, but I usually landed very strong ones against unprepped people or against races with low int.

Romantic is really the jack-of-all-trades repertoire, and IMHO, it's the best for anyone who wants to PK/group explore/raid/solo all in one.

PS: I didn't do this, but if you wanna get your fag on (or you're a chick), do a female elf romantic. With edges you're probably gonna get quite a boost, especially since 90% of the population is male.