I'm sure I'm not the only one with this quandary so hopefully this question is suitable for Mathoverflow. I'm posting anonymously for obvious reasons.

In a couple of my papers I have answered questions which were fairly well known inside my sub-field and posed by well known people. However, the solutions themselves are not hard - they do not involve any substantially new idea, other than perhaps the insight that some well-known techniques in a slightly different field could be of use. In the end I submitted (and published) to journals taking into account more the difficulty of the solution rather than the prestige of the problem. Several people later told me I could/should have aimed higher.

Now I am in a similar situation, with a couple of papers in preparation where the techniques I use are well-known, but they have just not been applied to the type of problems I solve (which again, are questions asked by very good people and open for at least a while. They are not major famous questions). Maybe I just have a good smell for low hanging fruit!

My concrete question is twofold:

• Generally speaking, are papers who answer a respectable open question judged more for the problem solved than for the difficulty/innovation of the solution?
• What are some good journals that welcome this sort of papers? (General journals as well as specialized ones)