I know that many players may not like the idea of a class change token, but I think that there are many good points to make for having one implemented while still making the system restrictive enough to not lead to abuse.
Not all players are interested in having multiple characters to have to manage. We often hear of people doing their daily "chores" of logging into each character to level up mount stats, complete skill lines (scrying, I'm looking at you), and finding skyshards. Yes, there are crown skill lines you can purchase to complete all of these items, but not every player can afford or wants to spend real money on completing skill lines faster. Utilizing PTS, we could see how a class plays and then decide to pay for a single token to change our class.
The benefit, and by far the biggest reason for me in wanting a class change token, is that I enjoy having a single character to log into (yes I have other chars on my account, but it's mostly to create a name I thought was funny), and having one character that has all recipes, motif's, praxis, etc learned (yes, I know you can use the bank to move items to another char to learn, but I just prefer to have one char to play on, and one char that is learning all the items available IG). Switching characters is possible, but I'd much rather just keep one character with an option to change it's class every now and then to make things more interesting, without having to think "I don't have crafting levelled up yet on this char so I can't do daily crafting writs".
In order to keep it from being overused, a cooldown on the token could be implemented so that you can only change class once every three months, and class changes would not be allowed to be saved in the armory (when you change your class, you change the slots avaialble in the armory). This allows users to play alternate classes without losing all the progress they've made, and allow them to have some variety.
The biggest example I can provide, is the recent introduction of the Aracanist class. I've enjoyed playing on my Arcanist character, but often default to my Sorc because that's the character I'm used to playing, and the one I'm trying to get to complete achievements etc.
One other option (which I would actually quite enjoy) would be that all story related skills could also be reset when changing classes. Skill lines would remain (ie: scrying, crafting etc) but all zone quests, and dungeon skill points are reset and I have to do those quests again. I'd love to go back to do zone quests without having to create a new character to do so, and this could help to achieve that.
Just a thought, look forward to reading other perspectives.