Naked Man and I have been going back and forth on comments in my previous posts about how exactly an RPG should be made in terms of how levelling up works and how characters gain power. There are a few different models to consider, like the 2nd edition DnD model where characters hit huge breakpoints in power that really changed their game. Fighters getting an extra half attack at level 7, for example, is a huge step up in efficacy. Mages hitting level 5 and suddenly being able to cast Fireball increased their offensive capabilities to an incredible extent. The other extreme is something like World of Darkness where every session the characters got a little bit of XP and it could be spent on absolutely anything - no abilities were based on overall character advancement. Right now Heroes By Trade is very much the second way because you get new things when you level up but a level 15 character does not have substantially different choices than a level 5 character.
Some people really hate the design where some levels are good and other levels are dead - that is, a design where you don't get to do something interesting every time you level up. Naked Man, on the other hand, dislikes that HBT doesn't have those huge levels where you suddenly become vastly more powerful than before. He wants something big to look forward to, something that unlocks at a certain point that you could not access before. Feeling more powerful because you get a big numerical increase is possible but I really don't like it much. A level that simply makes you do 50% more damage doesn't make combat more fun or grant interesting choices and it does create a scale of increasing power that is a much higher slope than I want for the game. However, it is possible to create things that require a substantial investment to acquire but which mostly add options rather than raw numbers. For example, I could have Rituals come in trees and require that people learn 5 Rituals in the tree before learning the most powerful one. That would create a longterm sense of accomplishment without necessarily blowing the scaling out of whack.
Personally I don't feel that big bumps in progression are necessary for my enjoyment. I am really excited to pick a new thing each level and that new thing doesn't have to make me extremely powerful compared to what I was before. Just moving along my list of things I want to do to get to the vision I have for my character at max level is great fun for me. I know the complaints I have seen about leveling systems have mostly been complaints about dead levels rather than about not having enough cool stuff to do so perhaps Naked Man is really in the minority here and most people just want to get something new and interesting each time and aren't so worried about saving up for a particular thing. I think I will investigate ways to add in cool new stuff in ways that requires substantial investment and thus can pay off later on and see if that feels good.