In the last month, I bought a pair of JBL 306P Mk ii speakers specifically for desktop use.
Unfortunately, I could not recommend them for this application, although, as always, YMMV. I found that listening from a distance of about 70cm (or 2 feet) at the levels I like to use (high 60dB to low 70dB, so not as loud as many people like, probably), the tweeter "hiss" (speaker self noise) was completely unacceptable to me.
I have many recordings made with a Revox A77 tape machine and these all have tape hiss that should be audible (it isn't objectionable normally, but you should be able to hear it). With the 306p on the desktop, I couldn't tell which recordings had tape hiss and which did not, as the speaker self noise was significantly louder. Also, the speaker self noise hiss seems to me to have a slightly "gritty" quality that makes it more objectionable than old fashioned tape hiss.
So, the 306p speakers have been moved to serve as "room speakers" (standard stereo setup). In this application, I am listening from a distance of about 2 meters (6 feet) or more, and the self noise is nearly inaudible and (to me) completely unobjectionable.
The sound quality (in my opinion -- feel free to ignore this!) is very good indeed when used this way, and would be very good whatever the things cost. Considering the price, the value for money is remarkable.
As the self noise is fixed at a constant level, how objectionable it is depends on how far away you listen and how loud you like to listen.
I think the Yamaha HS7 speakers have much lower self noise and also have a quite different (more neutral) frequency response than the HS5s. This is just from looking at data, though -- I have not heard them. Also, they may be too large for desktop use, as you mentioned. For my desk, the 306ps were on the edge of being too big (on on the edge of the desk, too!).
At the risk of mentioning the inappropriate, I am likely to buy some Neumann KH 80 DSPs for the desk eventually (if I can find some way of buying them where I live ... but that's another story). The combination of low self noise and otherwise excellent sound quality seems to involve spending 3 or 4 times more than the 306ps, unfortunately.
There may be less "professional" options, though. The Audioengine A5+ speakers reviewed recently measured very well and they seem to be around $400 (in some locations) ... no balanced inputs, though ...
I would suggest the speaker self noise specification (unfortunately, often not given by manufacturers) is a critical factor in choosing a descktop speaker. As I have found out the hard way ...