Well, that depends on a number of factors.
What vlf are you using? Some work better than others in hot ground. Etracs, for example, are notoriously bad. Mxts, blue and greys, f75s, and t2s tend to do better. At pros it seems to depend on the user, I've seen mixed results. I used a dfx there for years and did quite well for a vlf.
What are you trying to get out of the hunt? If you're coming from somewhere without cw activity and want to find a single Relic for your bucket list, chances are pretty good. If you want to get together with a bunch of like minded Relic Hunters for a unique and memorable time on incredibly historic property, you can't miss. If you want a hundred bullets and two dozen buttons and a couple plates... Check your expectations at the door. It's not impossible, nothing is impossible. But finding truckload of relics with a vlf is more challenging at many of those sites than a pi.
How much are you willing to work? The pis can, no doubt, find relics that the vlfs simply can't hear. I know because I've seen it first hand. But there are a lot of relics in range of the vlf, but deep enough to ruin your discrimination. So to get them, you're doing to have to dig a lot of junk signals. A lot. Like, really, a lot of iron. But it can be done.
How much are you willing to spend? You can pick up a used tdi pretty cheap. Or you can look into the rental route from jdug rentals. Both of those options might be more than you want to spend though, so its up to you.
I've gotten three plates, several nice buttons, two bottles, and a decent number of bullets from hot ground group Relic hunts with my vlf. Not saying this to brag, just to say that it is possible. That being said, I have used a gpx for the last few hunts, and it really does make a night and day difference in the ease of finding relics and the quantity recovered. But I personally don't regret going with just my vlf all those times, and i would do it again. I've made some of my best friends in the world at those digs.
