I can only speak from experience...I was dubious about real estate on the 13" screen but I was blown away. As Maflynn points out, delays to Intel's production of the new Broadwell chip are well documented, so I'd say go ahead. I Use my maxed out 13" for just about everything, and it's more capable than I thought...It will happily run Doom, Quake ( I know I'm an old guy) in full settings without missing a beat, and I have the stock 8GB RAM.
Only thing I would suggest is that you think carefully about RAM intensive Apps prior to purchase as this is a non user upgrade. I went for the 500GB SSD and the 3GHZ CPU.
Wouldn't be without it...I just sold my iPad and although I want a new one, I find this just as nice to use...It's not heavy on my lap ( I had a 17" cMBP before) and i can comfortably use it for hours on my laptop tray.