Due to their small size I believe these speakers aren't at their best even at 86 dB. It's telling that the Genelec manual specs harmonic distortion at 80 dB for these but higher for other models. Numbers from the manuals I have on hand:
8010a @ 80 dB 70-400 Hz <3% harmonic distortion
G One @ 85 dB 70-400 Hz <3% harmonic distortion *
8030c @ 85 dB 50-100 Hz <2% harmonic distortion
8040b @ 90 dB 50-100 Hz <2% harmonic distortion
8341 @ 90 dB 50-100 Hz <2% harmonic distortion
8050b @ 90 dB 50-100 Hz <2% harmonic distortion
8260a @ 90 dB 50-100 Hz <1% harmonic distortion
* Surprisingly the G One, very similar to the 8010 but with a 12W instead of a 25W bass amp, is rated at 85 dB.
I sit close and don't usually play my desktop speakers very loud so these would probably sound fantastic. I'd still go for a sub though.
I own pairs of 8320 and 8330s and have owned 8010s. The contrary to what I mentioned earlier, I prefer the 8320s as they're a bit more punchy and fast in presentation compared with the 8330s. I'm not a fan of accentuated bass. For example the HD800S headphones feel too bass accentuated for my preference, compared with the original HD800s which I like quite a bit. The 8320s without a subwoofer are perfect for a small home office/recording studio application imho.