I can't immediately think of any good online resources - my knowledge of this subject was obtained by designing and building brushless motors for a number of automotive applications a few years back. We had to experiment with both wye and delta winds because our motor geometry and winding equipment placed limits on the size wire that could be accommodated in production.

Probably the single biggest issue with delta motors is that some ESCs with less-sophisticated sensorless modes will not play well. Wyes are (relatively) much easier to commutate using 120-degree operation and zero-crossing detection on the open phase.