First time I have ever heard 'uMBP'
The 'cMBP' is the current MacBook Pro sans Retina display
Actually MBP or "MacBook Pro" is the current MacBook Pro sans Retina display. Per Apple anyway. cMBP for Classic MBP was a moniker some years ago to refer to pre-unibody models.
It's pretty confusing, I think we should just leave it at what it is, a MacBook Pro, and a Retina MacBook Pro.
As to the OP; depends on what you need it for. Upgradability is where the value in the non retina model is. If you'd like a 512GB SSD, for example, it's substantially cheaper to buy and install a 512GB SSD vs upgrading the SSD in the retina model. Also, if it matters to you, the RAM is capped at 8GB for the retina model, wheras for under a hundred bucks you can get 16 gigs of RAM for the non-retina. Useful for VM's or certain applications, but most folks won't need that.
tit-for-tat though, stock model vs stock model, there's a lot of value in the retina model. The extra thunderbolt port and HDMI port is super nice for running multiple monitors. I have a non retina model and have two beautiful (non thunderbolt) displays, but can only use one because I have only one video output port! (In this case one TB port currently acting as a miniDP port).
The deciding factor for me though, ultimately, was upgradability. I wanted at least 512GB of SSD storage, I also wanted 16GB of RAM (though that wasn't a dealbreaker). Running a 512GB SSD on a 13" Retina really spikes the price and put it out of reach for me. A $1200 MBP + $400 for a pair of 256GB SSD's configured in RAID 0 was a better deal, for me anyway. As a matter of fact I was able to add 16 gigs of RAM into that mix, an optibay, and an external superdrive enclosure and still make it out a couple hundred bucks cheaper.
If I had an unlimited budget, I'd go for the retina with a 512GB SSD though! If for no other reason than the multiple thunderbolt ports + HDMI.
By the way one of these threads pops up about once or twice a day, it's worth a read to scroll down a bit and see some of the other people asking about retina vs non-retina and see a lot of comments, and where those users ended up going.
True, although in all fairness, my 2007 classic MBP has recently been revived, and is now being used by my parents, after their G5 iMac died a week ago. It had its motherboard replaced for free, after the 8600M partially failed. Still works fine now though.
P.S. FWIW, I think if the OP is considering going for the 13" rMBP over the 13" uMBP, they should consider the 15" rMBP. It is around the same weight as the 13" uMBP, but is a vastly superior machine, and not all that much more money.
Form factor is a concern too though. It's not just weight, but it's footprint. There are some absolute performance advantages to the 15" model, but the 13" is 'fast enough' for many users today, and folks like me really really really prefer the 13" form factor, and find the 15" a little more unwieldy and a little less portable. It's not just the weight, but the amount of space it takes in a bag/lap/desk/table/etc.