Balsa repairs are not bad at all. My old Avistar is a fine example. But it's one of those things where I can't just bust out the medium CA at the field and glue a fuselage back together, you need covering and an iron, etc. I think a balsa repair ends up better in the long run. If it weren't for the patches in the covering, you'd be hard pressed to point out the repaired areas on my Avistar. My foam planes have ugly scars where they have been glued. With the exception of my HZ Super Cub which is covered in Econokote, most of my foam repairs are pretty ugly. From 5 feet away, you can't tell where my Avistar has been repaired, but it's very evident on my foam planes like my T-28.
EDIT: I am slowly getting better at covering. I have found that Econokote is much easier to work with than Monokote. I used Towerkote on my Avistar and it was easy too, but I don't think it quite has the same fuel resistance as the Econokote.