For us, t comes down to need, and want. The 23RB is enough and just right for me, my wife, and our little dog. Its simple, easy to haul with my Sierra 1500, and allows me to pack anything I want ion the bed or trailer storage, and travel with a full water tank when necessary without issues. When we see, or spend time in a trailer w a slide or slides, it certainly is nice to have more space to stretch out, but for us, as of now, it isn't necessary.
Our plan is to upgrade our truck in the next 5 years, in turn upgrading our trailer, for more space, but we could be just fine in our 23RB. Days when the weather is bad, and my wife is cooking, its tight trying get tot eh bathroom, but that is the exception of activity throughout day so its manageable.
Do we WANT more space and slides? Sure, as a luxury item.
Do we NEED more space and slides? No