I couldn't make up my mind either, so I bought both. Tried both in a heavily hit site just to compare. The ONLY difference I could see was the pro coil was lighter in weight. Otherwise, both coils hit good targets (deep silver, 8+ inches) and gave solid readings. I have no complaints about either one.
The slightly extra weight of the SEF can be dealt with by altering swing/scan techniques. I learned long ago how to avoid 'detector elbow'...which isn't fun at all....by scanning from the shoulder, with detecting arm extended straight, and shifting weight from right to left foot as you advance. You use that weight shift to help move the detector and you can go all day.
Knipper