Let me ask you this: If you were manually transcribing a piece of sheet music to create a MIDI file, what application would you use for data entry?
I'm probably not the best person to ask, but I'll give some suggestions anyway.

For simple monophonic melodies, BiaB is actually nice,
if you set the durations to 100%. You need to do this
before you start data entry.
I like
Notion, but I picked it up cheaply a while ago. The main selling feature (besides price) was support for multiple sound libraries, but they don't have the same level of support they use to.
I used
NoteFlight a number of years ago, and liked the ability to enter music notation by typing.
I've read good things about
MuseScore, and I remember asking for some features that ended up in the next version - something you're not going to get from a typical software developer.
For simple compositions, you might look at
Finale Notepad.
There are a
lot of notation programs that I've skipped here - I've mostly mentioned the ones I know that are free (or free-ish).
Really, it's like choosing DAW. They all get the job done, but there might be something that designed in a way that matches your mental model, or has some features you find important.