Yes, good point. I think that is a reason. Some local codes here are even requiring perfectly good fuse panels to be replaced even when non-tamperable fuse size adapters are installed. When there is no valid safety reason for a requirement I figure its Chicago union influence.

Nope that is a fact.

NYC and the big windy both have rules written by labor.

A few panel makers have 32 space 100A MB panels. I know SqD QO does for sure. I just used one recently.

Wow, never would have guessed 100 amps can support 32+ breakers. I guess you'd have to be careful not to overload it, though.

I'd say the biggest loads in my house would be the fridge, 10k BTU window A/C unit (on its own 20 amp circuit) and occasional space heater usage. The range, hot water tank, clothes dryer and furnace are gas. Not really much load in the house but I was planning on using the 50 amp breaker from the old range feed to feed a 50 amp sub panel in the detached garage at some point.

I also may have some drain tile work and a sump pit installed (ugh!) at some point so there's another 20 amp breaker. That will leave me with one space left. Not sure I want to jam a bunch of those slim breakers in, it's already sorta crowded in there (if it can even accept them, haven't been able to determine yet. Nothing mentioned about it on the sticker).

Might be worth it to upgrade to a larger panel and/or service when/if I do the garage project......?

Maybe I'll type up my current circuits and what they feed and post it.

Its not about the # of circuits. Loads are calculated according to the code using the load calculation rules. For example lighting/general receptacles is calculated at 3VA per square foot. The # of breakers and the amperages of breakers means nothing for load calculation purposes.

So listing my circuits won't really tell you anything? The house is about 900 sq feet.

NEC load calculations for a dwelling unit are to allow 3VA per square foot. Also allow 1,500VA for each kitchen appliance and laundry circuit (yes, they can handle 2,400VA but the assumption is they will not all be loaded up to capacity at the same time). Add the larger of the heating or air cond. load. Then add any major appliances using their load. And even at that there are demand factors for some loads that can reduce the value.
So the listing of circuits with appliance ratings is part of the load calculation, just not for lighting circuits (lighting and receptacles in bedrooms, living rooms, etc.)

With the newest code rules and dedicated circuits(kitchens, bathrooms, laundry etc) the count goes up a lot from back when the panel was first installed.