I find the current breakdown of functionality between Community and Professional confusing. While I understand that Odoo needs to convert users from the community to the professional edition to make money, I find it counterproductive that there is apparently no upgrade path from the community to the professional edition. It seems to me that the most common scenario would be a company testing out the community edition using their own virtualization hardware and the switching over if they like the product (most likely after some extensive testing, potentially in parallel with an existing platform).
In general, I feel that it is fine to reduce functionality, but completely eliminating it (e.g. mobile platform) seems to make an evaluation once again more difficult if not impossible.
On the pricing side, we do like the licensing option to select by module, but some pricing options don't make sense (e.g. sales [$15] vs time sheets, expenses and vacations [$45]). Needless to say that it is a hard sell to tell human resources that their modules are more expensive than the ones from the sales department.
Anyhow, we will continue our evaluation and see how things are progressing, but I thought it might be worthwhile to share some feedback I have received from my business partners.