I've been trying free limiters for a while and after many tests I concluded this is one of the best (Vlad G Limiter No. 6, Sonic Anomaly Unlimited, Loudmax, Xhip Limiter, Dead Duck Limiter, ReaComp with or without precomp, W1 Limiter and many others).
1) It doesn't have oversampling/antialiasing: This is something that only Limiter No. 6 has from any free limiter, and in terms of quality (mostly for mastering) should be a must for preventing aliasing distortion. It has another antialiasing technique involved though.
2) The VU meter is unreliable: Not because it shows wrong values, but because depending on the release it can operate really fast to see how much it's reducing. Also, it's too small to see how much you're reducing unless is kinda drastic (or if you resize the plugin a lot).
3) Release Knob: Just like the Waves L1 it has a manual release knob and this sometimes can be annoying as the only thing the plugin needs to do it's to reduce peaks, and finding the correct release time can take some time.
4) The threshold only goes down to -20dB: Not too much of a problem given that this plugin has Input and Output gain.
5) Latency: 87 samples as reported in Reaper 5.961 64-bits.