"If you took him to a childminder you may have the same tears and trauma at the drop off."
Although you may have the same separation issues coming up at a CM, the CM will be able to give your DS more individual attention, and structure the days more around his needs than a nursery which has so many other children's needs to consider.
Also, with a CM, you get the consistency of the same person all the time. In a nursery people come and go, especially if they have a lot of people on part-time shifts.
FWIW DS has just started going to nursery (just over 2yo).
We sent him to the nursery because it's a lovely nursery and because of the location it means we need 2 hours less childcare per day.
However he took much longer to settle in the nursery than he did at his second CMs, which he moved to at around 15 months.
He does seem to be settling now (6 weeks, 2 days a week) but I was on the verge of taking him out. If it wasn't for the extra 2 hours we get together, which I value immensely, then I would have simply sent him back to the CM (He commutes with me now, it's lovely - we look out of the window at cows and stuff
)
In retrospect if we were doing it again, I wouldn't move him from the CM to the nursery until he was at least 2.5 if not 3, and if we have another DC I expect this is what we'll do next time.
Of course this is only our experience and every child is different but HTH!