I do both.
I use the easier guitar (Gibson electric) to practice 'hard stuff' and much stuff that is new. But I also try to ensure that anything I play on that guitar I can also play on the more difficult, Martin acoustic.
I'm much more likely to play the acoustic in front of others, especially when away from home. It makes no sense to me to be well practiced on the guitar I leave in place and to be not be as good on the one I'm playing when I want to be the best I can. Further, easy practice may lead to hard disappointment when someone hands me [u]their[/u] guitar...
There is also an issue of sound and genre. Many genres/types of songs are associated to a guitar sound starting with the difference between acousic and electric. I'm more into folk and folk rock then I am into metal... my music interests lead me more often to the more difficult guitar. Still, I built my guitar stable to reflect different sounds; a Gibson electric, a Martin acoustic and an Ovation AE 12-string. They all play differently and there are specific songs I prefer to play on just them yet they all play with varying degrees of difficulty. If I stuck with just the easiest one I couldn't emulate the sound I want quite as well.
Keep the learning enjoyable but don't shy away from the difficult (see my forum signature below). On the other hand, it's a time-honored tradition to search for a guitar that 'feels better' and is better for you.
My guitar playing, such as it is , stands on three legs; patience, much practice and well thought-out guitar choices.
Good luck, have fun.
"It takes a lot of devotion and work, or maybe I should say play, because if you love it, that's what it amounts to. I haven't found any shortcuts, and I've been looking for a long time."
-- Chet Atkins