Hi Norm,
I have a sample of the Multi Kruzer and have run some tests. In terms of stability on the wet sand and in the water, as with the Impact, I am finding 14 kHz the best option. 5 and 19 kHz work, but 14 kHz is just slightly better....but I'm sure different beaches may give different results. I also find 14 kHz the best all round for most common coin sizes and gold rings that I've tested. BUT, 19 kHz does have a bit of an edge on very fine rings, chains, earings etc. even if requiring a slightly lower Gain setting. Sometimes a slight improvement is all that is needed in order to hear a target. Hope to do some videos when the wind isn't blowing hard.
So, the 14 kHz Kruzer represents great value, and all-round performance, but if you want to have the edge on low conductors, then the Multi will be the way to go. Most beach hunters here are using BBS or FBS machines (I still use a Sovereign with big coil when I'm chasing depth) but I know they are quite poor on fine jewellery, so will definitely be adding the Multi Kruzer to the arsenal, to work those eroded gutters where jewellery is often hiding. I will also most likely add the open web 9.5x5" coil for even more sensitivity, as this coil has been great on the Impact.