I like the Audioengines 5+, I think they're very well-executed. They measure pretty well when placed a few feet from the back or side walls too. In fact, that seems to be their weakness for the desktop use case, IMO. They seem optimized for placement in a classic audiophile system as the main speakers. Placed on a large desktop a few inches from the back wall I measured a 13db+ spike centered at 120Hz, which was less than 3db when the speakers were moved to the front of the 3' deep desktop, the drivers slightly overhanging the edge. As I documented in this thread:
http://forums.audioholics.com/forums/loudspeakers/90509-boom.html#post1031139, I fixed the spike with EQ software, but clearly the 5+ doesn't appreciate being very near a back wall (and two feet from a room corner on the left side).
If your desk faces out into your office, so the 5+ doesn't have a wall behind them, they might be just about perfect. They also produce a surprising amount of bass, even out in a room. For some reason I just never expected a speaker that small to be capable of 40Hz. Sometimes I'll have an action movie playing and some bass impact will startle me, because I'm not expecting any audible deep bass.
I also admit I liked how the 5+ look in white. It goes well with an iMac.
IMO, pro studio near-field monitors, like the JBL LSRs or the Mackies sound better without equalization than the 5+ on a desktop, because I suspect they are equalized by design to sound good at the end of a mixer board, but both are far more expensive, especially the JBL at over $1500.
