Probably to late to be of any value...
I've owned an SE84CKCS for about a year driving a pair of late-70s Cornwalls. Your Forte IIs appear to be a half dB more efficient, so beyond saying you should get more Quality Loud for your 2.3 Watts/channel than I do, no further comparison is offered. One disclaimer: I had balanced inputs added, and am using an Oppo BDP-105D as a direct source. Back on the beam...
Overall, I'm happy. I've done some mild tube rolling. If you go with this amp, I would suggest not bothering with swapping in rectifiers of output tubes: What comes with the amp is fine.
The input tube is a different story. The amp ships with a 6N1P-EB (a Russian military entry in the 6922/6DJ8 family). I dropped in a vintage 6DJ8, getting incredible top and mid, giving up a significant amount of low frequency response. Soundstage and depth were fantastic. The other end of the spectrum is the 6922. With a vintage Amperex, the 6922 top is not as good as the 6DJ8, the mid is, and the bottom is far better. Overall, the 6922 sounds balanced and "right." One odd bit: While the soundstage of the 6DJ8 sounds better, the depth with the 6922 is superior.
The 6N1P-EB falls in the middle.
