Are transition bags worth it?

I have a several different Ironman branded bags purchased or given to me over the years.  PM me an address and I'll send you one. I could do with less bags. And you sound like you could do with +1.

Many years ago, I bought a super nice transition bag with all of the compartments and bells and whistles. I think I've used it twice. It's WAY too big and overkill for my needs. Even in an Ironman - where they assign you separate bags, eliminating the need for an all-in-one product. Maybe at the half iron distance, one that is wetsuit legal where I could use the wet compartment, I think I've used it for one of those. But even then just a regular ol' drawstring bag suits my needs - I can wear a drawstring bag like a backpack, throw my helmet on and ride my bike to a 70.3 transition with no issues. Throw in a Wal-Mart plastic sack if you really need to separate wet from dry (is anything dry at the end of a race??). I've learned over the years for me, simple is better.

Now, I use the transition bag for (non-triathlon) traveling. If I could go back, I wouldn't purchase it.

My only advice is that too many pockets are just as bad as none. I've stowed things away so carefully I don't find them for years.  I had a TYR transition bag with mesh divider pockets on the inside. I eventually just cut them out.  I personally prefer a simple backpack plus some plastic bags for things as needed.  I put phone and keys in a plastic bag since transition can get wet, it can rain, etc.   If i will need dry clothes for after, I put that in a plastic bag at the bottom.  Other than that, it's all race related stuff that comes out for race time, so doesn't need to be separated.

I personally use a $20 backpack from Costco. It has 2 large pockets (one separated by a laptop divider), 1 medium pocket, 1 small pocket, and a water bottle pocket. I have a pre-race checkist; the OCD in me led me to adding the location of each item within the backpack to the checklist. I then attach one of the cheap swag bags with my wetsuit to the outside. I find it's been very useful.