What would you set the high pass crossover to?
I set mine to 50 Hz. It's a 24 dB/oct filter so it rolls the bass off very quickly. The goal is to avoid sending the speakers a signal below the tuning frequency of the enclosure, at these frequencies the enclosure does little to nothing to control the motion of the cone. At frequencies above the port tuning the cone motion is very well controlled... this is the big advantage of a ported box, the cone excursion is far less than a comparable sealed box.
The 50 Hz xo point makes integration with a sub very easy and you would not believe how much sound those little drivers will put out with the high pass engaged. Even without xo they do very well for their size but with the xo the SPLs you can achieve are absolutely amazing.
I did re-build my EL34 SET and with the new configuration it's a good bit better than the Crown, but it's still not night and day... the Crown is pretty amazing for a couple hundred bucks!
You will want to order Pomona tellurium copper binding posts though, they bolt-in without soldering and make a big improvement in terms of added grain. The Crown is not perfect in this area and it's mostly the connectors/jacks doing the damage.