I just got my H688 for $113 and realized that it is slightly different than the SST-688 in the comparison picture.

[Link: assets.logitech.com]
The H688 seems to be an update to make it more like the 676/680.
The direction circle & ok button are now the same as on the 676/680 and the LCD backlight is the same blue/green instead of the purpleblue in the picture. I am sure this is to reduce costs by using the same parts.

The other thing that seems to be different between the H688 and SST-688 is the button material. I don't have an SST-688, but the buttons on my H688 are translucent and rubbery like the 676 not white like the picture of the SST-688. Are they really white on the SST-688?

I wasnt sure if I should have gotten the 676 before I ordered, but now that I have the H688 I am very happy with my choice. I like the VOL+-, CH+- and direction control all being on the same line and where my thumb naturally falls when I pick up the remote.

There have been very minor product updates over the years. The Harmony remotes originally had SST (smart state technology) as part of their model numbers, but around the time that Harmony was acquired by Logitech, the SST changed to H (Harmony).

Glad you're satisfied with your purchase.