This is a common criticism of Rel, the cost to performance ratio is simply askew.
When it comes to time domain/ group delay, the modern Ported Subs all seem to behave very well, and as you say, the output is higher, tune lower, and usually more efficient in terms of output, especially lower in the frequency range.
I’m not knocking sealed, or rel, but the other aspect to look at is your own usage: room volume, open or closed to other areas, music only or ht, what type of music?
My own rule because I enjoy pipe organ is that I want something that will be capable down to 16 hz. I also use them for HT.
In the end, this is where you have to decide what your personal values are (not cost values) and what you expect/demand out of your system performance.