I recently bought a 15400 silver/white dial and it is certainly more dainty than my previous ROO diver, which picked up many scars over the years on my wrist, so I am saving mine for 'occasions', as do not consider these look great with too many marks, which is inevitable on the bezel.
I bought the no date black dial, so yes, 41mm, no date function, but obvious similarities. Felt very light and cheaper than its price point and the internal bezel moved very easily with the glance of a shirt cuff on the crown. Sold it very quickly (and lost money) and I'm a massive fan of the brand,
No doubt, the favoured watch size is 40mm, so many find the 42mm current Pelagos too big. For me, it's perfect, but this will be very popular. Question is, will they discontinue the 42mm - who knows...
I do exactly the same, but some like to keep them factory fresh and I say, do whatever takes your fancy. Personally, I take the view that a watch can be sent for a freshen up/repair/etc., so wear as intended.