Hi @James_Longley1,
and welcome to Coda Community 
I see your point: from a content perspective it seems quite unreasonable to see interesting yet “irrelevant” features according to your urgencies.
I’d like to say that I’m also very much focused on performance issues, so I totally understand your frustration.
However, in this 18 months of extensive use of Coda (for myself and for my clients) and a real active participation in this community, I see why there is a broad range of features and therefore a weighted attention to what is still an evolving tool.
Aside from the latest much appreciated announcement (Launched: Improvements to doc load & performance), we all know that adding a feature - like pronouns in profile - and working on performance are completely different things altogether.
With a cost-to-benefit ratio that has to evaluated in the client/prospect audience.
Performance boost is definitely something structural that relies on design, compatibility and reliability and it has a long - typically infinite - roadmap.
At the same time, there is an army of very well motivated people who demand UI improvements because these are must-to-have-no-matter-what requirements (and they are right, of course!).
I think that Coda has its double edged sword in its flexibility and we have to keep constantly asking ourselves if our expectations about this tool are appropriate.
I warmly invite you to share your document needs (also privately, if you prefer) and see if another approach might be possible.
There are extremely skilled people here and I’m sure this can lead to a great advantage.
Included the one that let us choose another direction or another technology.
Cheers!
Edit:
Basically what @Paul_Danyliuk just posted, but we submitted it at the same time! 