Cool - so I guess you're asking which is the "cooler" of the two solutions? If it was me - I'd go for the NodeJS and MongoDB... because I haven't got a chance

Cool - so I guess you're asking which is the "cooler" of the two solutions? If it was me - I'd go for the NodeJS and MongoDB... because I haven't got a chance to build anything meaningful in either as yet. And also because I think MongoDB's geo-spatial stuffs would be useful for your project.