I think it also depends greatly on the areas that you wish to detect, depth of regolith, depth history of nugget finds, whether you want to cover a lot of ground quickly, What "targets" you are looking for, Temperature and time of year, soil mineralisation of the area you are detecting, EMI on the day, and the bloody list goes on and on.
You say you have the Whites gmx vlf for small nuggets, but how small is small? Are we talking crumbs in the sub gram range, or bigger? Then you can also pull small nuggets deep in mineralised areas with a larger DD run in sharp on the 5000. I suspect depending on the size of the "small" nuggets you are talking about, the one detector/coil set-up will out perform the other, when all of the above variables (and more) are taken into consideration on the day.
I only search for big stuff in deeper large gold areas in Vic with a large coil on the 5000, and anything small that I may happen to find I consider bycatch. Having said that, if you are going to simply detect and slavishly follow the same hammered gullies and well known areas that 95% of the detecting population do, those areas have been hammered so hard, and picked over by so many different set-ups that you will probably be lucky to find tiddlers if any.
We are all different. I don't need to come home with gold every time I go out to consider it a good day out. We all have different attitudes to risk, and sure it all adds up, but then so does your time walking this planet potentially missing big targets just so you can walk around with a little film canister in your pocket to pull out and show off at the next BBQ.
The deepest I've pulled anything out of the ground is around 700mm deep with the stock 11" DD minelab commander coil, but that was a complete 1850's miners pick-head at the foot of Mt Moliagul in wet ground, and the thing was probably about 18 inches to 2 feet long, rusty steel, and probably had a huge mineralised halo around it from the last 150 years of corrosion. It started off as the faintest of signals that I almost missed, and only grew to a fully recognizable signal the deeper I dug.
I've had a good go around Rheola and found little (bearing in mind that most of the biggies around there were found at eight or nine feet deep or more, and no detector with any kind of coil, on any kind of day will find anything that deep). But I have pulled a 1.5 grammer with the 25" DD-X NF in mineralised soil, in an area with lots of annoying charcoal, a couple of hundred mm max down, on a freezing cold morning when the sun was barely up, and I could run the 25 in sharp and the gain higher than usual, and there was bugger all interference.
I've never used a VLF myself, but personally I think if you've got something good for the crumbs and you want to find stuff bigger than that, you couldn't go wrong just playing around with the two 11" commanders, DD and Mono that come with the 5000.
Just my thoughts, and Merry Christmas
-D.S