I can run that setup when I head down to the drier more open goldfields of central Victoria. (I live in the mountains area of N,East Vic where the undergrowth is much thicker) I really liked the 14x9 as it seemed to balance the machine better and gave more coverage and was plenty sensitive on small birdshot. I also found a .4grammer with it.
I tried the 10x5 out over easter and found it to be very prone to falsing when knocked on the RH side. It was also harder to pinpoint a target with although very sensitive to small targets. The only plus over the standard coil was the fact that its pivot point being centred stops the tendancy to kick up the toe of the coil like the standard one does with its pivot point at the rear. :/
Changing from standard coil with curly cord up the centre of the shaft to coiltek coils with external cables is a fiddly job that really cuts into your detecting time.
I have them all 14x9 11inch round and 10x5 plus stock coil all good love the 14x9 for coverage 10 x5 extremely sensitive 11 inch round havent used much stock coil awesome great to have a choice when ground conditions require it but you cant go wrong with the stock coil havent used 11inch round much due to conditions my son bought it for me but when I find a patch I will use them all then call him over with his zed stock standard is great but if you choose to change and can afford it why not cheers Muk.