@aluaces Thanks. I's nice of you to answer. I was hoping for an oppinion from someone who uses (or has used) it already.

@mc the main advantages that are usually mentioned and the reason I am going to use it in the future are:

1/ since you have to write a unit, decoupled from the timer, you can start the job at will, specially important when debugging.

2/ you get a nice entry in the journal for each unit, so you do not have to grep the full logs or ~/dead-letter.

3/ much more control of the start of the process (simple, forking, etc), important when the jobs can overlap themselves.

4/ related to units: you can restrict the available resources of each job (for example limiting the directories it can access)

5/ I'm sure I'm leaving out more...