All things being equal (hypothetical) which do you prefer, XLR or RCA?

Appreciate all the great responses, thank you All! Sounds like XLR is for the most part what most prefer. Like I said I have gone balanced now and will not go back I was just more curious than anything else to see what most here prefer. But I definitely appreciate those of you that have done comparisons and shared your findings in your own systems, so thanks for sharing!

Locking grip?, sluggish? 

Over short distances they sound exactly the same. Over longer distances balanced cables have a theoretical advantage but I doubt any of us could reliably tell the difference. XLRs are certainly more ..hip. They lock in place which is nice. For those of us that use mono amps behind the speakers they could be considered mandatory and this is where they first entered the consumer Hi Fi chain then got generalized. They make sense for turntables which are balanced from the get go. Sound different? In your dreams maybe.

Many comparisons with various gear over 2 decades shows that dynamics are better, contrast is better, low level detail is superior and bass definition and impact are improved with true balanced XLR cables used with true balanced gear ⚙️ 

I have recently started using the XLR version of Van den Hul The Second instead of the RCA version (both one metre lengths) between pre-amp and power amp, and have been pleased with the outcome. Not an earth shattering improvement, but to my ears there has been a subtle change for the better.

I agree with dave_b. I have even noticed a big difference using an XLR  jumper from RCA too XLR.