Personally, I believe that having presets is a huge quality of life to have as it makes everything you're going to do so much easier/bearable. Obviously depending on which aspects you're looking at it from, it has its ups and downs. PvP:
Being able to have presets which affects both spellbook, prayerbook as well as inventory/armoury is insanely beneficial for the PvP aspect of the game. As i'm a new player I'm not sure how active the wilderness is on this server, but I can promise you that having presets will make the life of those who enjoy PK'ing much easier and it'll encourage them to go back and fight again - as they don't have to manually pick out everything from bank over and over again.
Especially if you're able to save presets, being able to save a NH preset, dharok's preset and things like that. Basically, this is a very beneficial piece of content for the PvP aspect. And honestly, it's 2020, if I had to manually grab myself a new mage set, runes, spellbook everytime I want to change a style or anything else, I probably wouldn't PK. PvM:
Again this goes back to the same as PvP, being able to save different kinds of presets depending on which style you're wanting to do, is again very very useful even for PvM'ing. It's not to the point where it gets broken so any argument saying that is invalid, you simply just get an easier time to do what you want to do instead of having to re-collect items every single time you want to change a boss, or even do the same boss repeatedly. Skilling:
The only issue I can see people having with presets is the skilling aspect, and that's because, well, it does making skilling A LOT easier. I'm not sure if you've meant for skilling to be a hassle or somewhat a long grind, but presets will definitely make the rates that was once before; a lot higher. However, if this is an issue, you could always make a list and blacklist certain skilling items in order for it no to become as powerful as people are afraid it'll be. Again, I don't have much experience with the server, but if skilling is a reason not to add the system, then keep in mind it's always able to be adjusted to the point where it's balanced.
Overall... yes, it's a great addition and I believe it's one of those qualities of lives that makes the server more enjoyable!