I've owned or used only a few sprayers over the years, but here's a couple thoughts...
I absolutely hate tow behind sprayers for my type of food plotting A lot of my plots are small or laid out in strips with little or no room to turn a tractor around at the end of the plot. Backing in or out is the only access. Backing a tow sprayer in tight spaces or around bends is slow, tedious and just plain sucks. The shorter the tow bar the harder it is to back up a trailer and most smaller sprayers have a tow bar that's 6 feet or less.
My current sprayer is a 25 gallon Fimco and it's just okay at best. Fimco could sure make a few minor improvements and make it a lot more user friendly.
#1, The stupid tank design doesn't completely empty when spraying, especially if being used on a slope when the tank has ~5 gallons left. As soon as the tank is tilted, all the solution pools away from the intake hose. During the period of a spray session when that happens, causes sporadic spray patterns as the solution sloshes around in the tank...lots of skipped places without herbicide applied. It also creates a few gallons of left-over spray every time. I either have to store it or put it in a hand sprayer to use up. It sure would be nice if Fimco used 99% of the solution in the tank regardless of the terrain.
#2, My other complaint with Fimco is the stupid little, undersized drain fitting on the tank. Flushing out a tank after each use takes much longer because the drain is so small. A 2" or 3" fitting would make the job much easier.
I think this aspect of food plotting is my least favorite. All the different chemicals, their storage, and the complications of what can be mixed and what can't be mixed, which chemicals can be sprayed on which weeds and when. The soil residue of some herbicides and the planting limitations they create. I'm not crazy about the clean-up of the tanks with all that contaminated rinse water. The expense of some of these herbicides is ridiculous.
Glyphosate is probably the least complicated herbicide, but I still don't care for it.
Yeah, I spray about a half dozen different herbicides every year, but I really don't like the whole procedure, and junk sprayers just make the job less desirable.
The only sprayer I really like is my 4 gallon Solo backpack.