Google IO talk on Maps Usability

I was interested to watch the Google IO video above of Designing Maps Applications for Usability on Mobile and Desktop by Luke Mahé, Jez Fletcher, Justin O'Beirne as a while back I had a go at presenting my own map design ideas to developers. The other week I said I've stopped critically reviewing other people's projects but when Googlers stand up and present about map usability I think some critical discussion is deserved. Here's some thoughts in note form:

Stuff I liked:

• Mobile vs Desktop: I don't do much with mobile maps so it was interesting to have the differences between mobile and desktop discussed, I liked the idea that users on the desktop are 'planning'
  
• Rendering Speed: Fast response is an integral part of the UX (user experience), I haven't really thought about this before except for very slow rendering maps so the discussion at 21 mins in was useful.
• Emphasising: Justin's points about how to use the GMaps API to demphasise uneeded map elements (30mins onwards) were smart and well made. I liked his examples of both good and bad maps.
• White roads for routes I especially liked Justin's point about making roads white for route focussed maps (36 mins), he's right that it emphasises the route well.

Stuff I didn't:

• Placemark Clustering: At 14.29 Jez and Luke promote the idea that a placemark clustering visualisation is better than not clustering points. Strictly they're correct as it is a way of tackling the 'too many points' problem but I think placemark clustering is flawed and not as good as other techniques. It should be said that this is my opinion - it may be that the clustering they show is actually a very effective technique, the proof would be a user test (which I will have a student looking at later this summer). My point is you shouldn't promote an unproven technique.
• Walk the Walk: It would have been good if the heat map Jez and Luke presented at at 14.58 had heeded Justin's smart advice and faded the background so the mix of colors stood out. To be fair, I guess it wouldn't have been straight forward to do this as it was a fusion tables map visualisation rather than a straight instance of the maps API but it can't be that difficult.
  
• Missing Topics: So they covered a lot of topics but there's a of UX things that IMHO are relevant to developers that I discussed but which failed to get a mention: Layer control, Icon design (although they did point out that you should choose useful icons rather than just use the default markers), use of color, balloon design, map copy/micro-copy and introductions.