There's several reasons I use my Sunray and wouldn't think of using anything but.
The main reason I like it is it saves my knees.... and my targets too! When I get a signal in the field I quickly pinpoint it, cut the plug with my shovel, then hit the switch with my right hand and grab the probe as I'm dropping to the ground. Now down on one knee I yank the plug with my left hand and start probing with my right. If I need my hand digger I reach back to my pouch and get it. This might sound like a lot reading it, but when I do it it's all in the matter of a couple seconds. The button is switched and I have the probe before I'm even down to the ground. Now why is this my way of doing things? One reason is it saves my knees from having to get back up and pinpoint the target again. The alternative which I assume most others do field hunting is use their shovel to dig out the target completely. Sure that works, but there's no question there will be times where you scrape your find. My detector is very good at finding targets on edge which means they are difficult to pinpoint and often end up in the side of the hole. Without a probe all you can do is guess, and cut out part of the hole and hope you don't hit it. I'm not sure if I explained my process well but there is no question it saves my targets and my knees, and I think it makes my recovery faster too. Remember what I've just described I've been doing for about 8 years straight, so it's pretty automatic.
A couple other reasons I like it is checking iffys and getting a bonus find now and again. The iffys come when a site is getting very quiet and I'm down to digging the very low % sounds which are almost always smaller iron. With the X-1 all I have to do it cut the plug, stick the probe in to confirm good or bad target, then either dig, or in most cases move on to the next. When doing this type of detecting, aka working the hard targets out, it's even more of a numbers game than regular detecting is because most targets are bad. Without the probe I would have to spend much more time on each hole to determine whether it's worth more digging, and in most cases I would have to keep digging to be sure. The 2nd thing, the bonus finds is when you are hunting in very heavy iron, something like a cellar hole that's never been ploughed and the targets are very masked by iron. In a spot like that everytime you dig a target you probe the entire hole very well and sometimes will get another find which was probably masked from surface detecting. I usually don't hunt sites like that, because they aren't here, but I did on a trip once and found 2 or 3 extra targets just in the dozen or so holes I dug. Having finished those thoughts two more come to mind. One is it's very easy to lose small targets once you get them on the surface where heavy iron is around, and the other is there's been some real deep stuff I probably would have walked away from had I not been able to stick a probe down the hole. I do hunt some days without the Sunray mostly due to weather, and each time I do there's at least one target I lose that I know wasn't iron. It's a drag to think that could have be "the one," and makes me wish I had taken my probe.
Anyway, that's all in relation to an Explorer but think it probably applies to other detectors too, and maybe some probes. For people that don't think they need a probe that's fine, but if they think they are not a great tool for others than they are dead wrong. I'd pay 4 times the price for my Sunray if I had too because it's cheaper and less painful then getting new knees!
