My developer's perspective to Germany:
If possible, because it's under 2kg, I like to use EUB. I think I never gotten a single question from customs with EUB. I do think however, that it's wrong to imply causation, it most likely has nothing to do with EUB and would look the same with DHL if I sent parcels that small.
DHL is my favorite over 2kg. The risk is low, but I've gotten used to the risk of customs, I'll pay the few extra bucks without complaining if I have to, it's still worth it.
The only thing I will never use again is EMS. I got 5 out of 5 parcels confiscated by customs, which I had to pay for. But that doesn't mean EMS doesn't work for your country, I heard wonders about it for other countries.