The reasons which prevents me from working with sexy technologies

You can get out of callback hell by using named functions instead of anonymous ones. Or, you could use a library to help control flow, like Step or Async.

Can't say much on Redis - used it once, but not the proper way - the only machine I have access to is a Windows one.

As for MongoDB, if I wanted to find one user who's name is "Jeffrey", much simpler to write User.findOne({'name': 'Jeffrey'}) than use a query language at all. MongoDB's "query language" is essentially just JavaScript...

Complexity in mongo comes from querying multiple collections in order to achieve a result. Querying one item out of one collection is trivial