At about 2:00 a.m. Sunday morning, May 13 I took a quick look at the overcast sky and saw one star, Vega. Figuring Mars was in the same range but lower I went out to my Palo Alto backyard's best southern viewing spot where my scope is sitting. The orangish ball was visible, although dimmed down a couple of magnitudes by the overcast. I ran inside for my eyepieces and it brightened up considerably, a veritable southern sucker hole, but that's all I needed.
Mars looked good at 300x despite mediocre seeing. Once again a Brandon 8mm outperformed a Nagler 9 on my 2350 mm focal length SCT. Sytis Major, Hellas and some other features were visible although displaced from last weekend at the same time. Since I had a breakfast date I didn't sketch, photograph or analyze each feature, but it was well worth doing on a night when nothing else was close to visible.
Mars seems to respond to higher magnification even in poor seeing, unlike say Jupiter. I'm guessing its because the features are more obvious, with higher contrast and less need to look at delicate little festoons and whorls.