I had a set (pardon the pun) of SET 45s. My speakers are 98 db. There was no-where near enough power...
So I built up a set of type 45 push-pull amps just for fun. Instead of about 3/4 watt, now I get something more like 5. So about double what I got out of my 2A3 SETs that I also had. One thing is for sure: the P-P 45s sound a lot better than either SET did before, regardless of volume- deeper bass, more extended highs, far more neutral and engaging in the midrange (nevertheless my 30-watt OTL took it to task immediately but that is another story).
DHT (Directly Heated Triodes) have a lot of linearity, but I don't see people comparing P-P to SET much in this realm, mostly because P-P DHT amps are somewhat rare. But I would consider it- you always want the amp to have essentially unlimited power regardless of the speaker for best result. With the Klipsch (depending on the room) that might mean 15-30 watts to really never be pushing the amp hard.
The problem with SETs is if you need power, the more power the amp can make the more the bandwidth is limited. By the time you get to 7 watts, most of them don't have much bandwidth below 30Hz (if they do then there will be no really high frequency extension...). This means that there will be colorations translating to lack of impact up to about 300Hz. But getting well below 15 or 20 Hz is no problem for a P-P amp, even if it makes 60 watts (and you can still have the HF bandwidth).
Now usually SETs are more transparent than many P-P amps, but if we are to compare apples to apples that P-P amp really should be using DHTs. If its a pentode amp *of course* the triode amp is going to be more linear...
The nice thing here is that with the Klipsch you pretty well can run whatever you want- its friendly to all known amplifiers.