I use both fremantle and harmattan on a daily basis. I would say that I enjoy using my N900 more, since it is the more flexible device. The concept of "mobile computer that happens to include telephony" meshes very happily with how I use mobile technology.

That said, if I need to take an important business call, or am in any situation where reliable telephony is the priority, I will tend to use the N9. Granted, the quality of the N9's hardware is a big reason for this, but certainly harmattan's feel as an "OS designed with a mobile phone in mind" contributes to my preference for using the N9 in those situations.

On a side note, since the N9 users were a bit more dependent on the soon to be shut down Nokia store for applications, it seems worth discussing what we as a community can do in preparation (e.g., encourage developers to upload to open repos), or whether a community response is even necessary (e.g., it is up to the individual user to save his/her required .debs now before they go away), or something else.