Here's the major problems that I have with wilderness diaries:
#1- Warbands
You have pretty much 0 chance of looting if you aren't in a team that doesn't leech. I've tried this before, and died many times trying to solo warbands. This pairs along with the fact that I don't like using teams for pretty much anything.
#2- Pkers
The problem isn't pkers themselves, but, for some reason, whenever I'm in the wilderness and don't have anything of value on me (less than 20k), I always get attacked by them. One time I was doing a wildy wyrm slayer task with a rune full helm risked at the most, and a team of 2 tried making me skull and lose my noxious staff, along with my ganodermic armor. A very long time ago, when I used to kill revenants at the cave, I used to risk only a couple of prayer potions and some sharks, yet I would get pked about every 5 minutes from scouts for pking teams. Quite an inconvenience, right? I used to pk many years ago on wilderness worlds, but I grew out of it after ~March 2012.
#3- Almost multi-combat everywhere
This goes along with the fact that the wilderness is multi-combat almost everywhere, so, if found by a team, there is almost no chance of survival, without a team of your own.
I can think of more reasons, but these are the biggest reasons why I don't approve of wilderness diaries. I'm not thinking about getting a comp cape at this time, but I might in the future.
Well, now I'm not sure which 99 to get again. I have about 3.3k mahogany logs stocked, 3k grenwall tickets, 50 hours of runespan, and a few of the armors/weapons I use at levels 8-11, but I'm not sure which 99 to get next.
-87 construction
-84 hunter
-93 (nearly 94) runecrafting
-91 invention
-83 divination
-80 defence (saving for last, since its the easiest of the bunch)