The original RPi model A had 256 RAM and fewer ports.
The original model B had 512 RAM, which is truly a minimum for trying to run a GUI like Raspbian.
Yes, I realize we used to get by with much less (the first PC my family owned -- when I was old enough to drive -- was a 386 16 MHz with 2 MB RAM. I used DOS though, I didn't even bother with Windows 3.1 since the machine couldn't handle it.)
But this is 2016, you know?
I do like the portability and the price. I'll probably get a Rpi 3 eventually.
Another problem -- though it's portable and you can have your computer with you everywhere, you DO need a modern monitor for it. That is to say, HDMI. You'd be surprised how many people have only VGA (3 rows) for monitors, the white DVI plug if you're lucky. And how many people still use composite or RCA plugs for their TV set -- no HDMI yet.
My mother-in-law watches a lot of TV, but she's still using a hand-me-down big screen TV that someone gave her. No HDMI port. She'd probably save money (on electricity) by purchasing a flat screen for $300, plus it would have state of the art ports like HDMI.
Also, the last time I stayed at someone's house, they didn't have a modern monitor to plug into. No HDMI, in fact they didn't even have a white "DVI" monitor plug. (I do own a single HDMI to DVI adapter). But of course HDMI gives you more than video -- it carries the audio signal as well which is SO convenient.
But forget about my mother in law, how about my own household! We don't have any HDMI TVs/monitors except the one I bought pretty recently. So if I wanted to bring that little PC into another room (for a Trad themed conference, some kind of viewing, a docuмentary, something educational for the kids, etc.) I'd be out of luck.
And although this PC is $35, monitors are still at least $100 to $200 for a flat screen with HDMI.
I noticed that all modern electronics want that HDMI port -- Raspberry Pi, OUYA game console, my Intel NUC (a small, ashtray sized computer), even my current PC. I believe game consoles all use it as well. It's where PCs and TVs have truly converged.
As a matter of fact, my latest monitor is a 32" flat screen TV with an HDMI port. I don't even get any reception (no antenna, and I live in the country) but it seems to be the way things are going.