To get a slightly roomier keyboard and bigger screen I'd pick up the XPS 15 Developer edition if it were created.  But is it just me, or in this day should a machine with 'developer' in the name be able to support 32 or 64Gb or RAM? 

So, an XPS 15 with ubuntu and 32+Gbs of RAM would be a slam dunk for those who write code for a living.