The 1st EUOS/SLAS solubility Challenge was a great experience for all authors, in particular to the first author, who learnt structure-activity relationship study approaches when working on this challenge and preparing her BSc thesis. One remark would be that the organizers could have described the challenge rules better to avoid any confusions as well as to eliminate any information (e.g., data labels, or data ordering) which is not relevant for the challenge. The absence of such information would avoid misinterpretation of the challenge rules by some participants, who contribute high scoring, but ineligible solutions. Another example was "Can we use other dataset?" discussion. Some of the authors of this manuscript interpreted the remark that "... any extra dataset competitors might use, if produced with the same protocol we described, can anytime be used", as permission to use additional measurements coming from the same protocol. In this case the extension of experimental data with new measurements could provide significant advantages to some participants, who have an access to such data. This caused some frustration, but did not stop us from participating in the challenge.