Is it better to use cycles now that I have a really good graphics card?
I would say the best thing to do would you improve in cycles, because the performance of your machine would work faster. (For me!)
But when choosing a renderer is a very relative question because you have to take into account other factors such as taste, functionality, and performance technique.
So I recommend you know the cycles and see if you adapt to it, then you choose the best option for you. ^ ^
there is no “give it up” at least for the time being. you still need it for texture baking, smoke and other stuff not supported by cycles.
there may come a time when cycles has full functionality but until then theres no need to even consider the question
I had the same problem. Now I’ve a GTX 660 Ti SC +78Mhz and my skills about of Cycles were improved a lot (see me in blendswap.com under blend2cap)
So, if realism is you’re passion/duty/need, forget BI and go to Cycles (or Octane, if you’re new in Cycles, because Octane is faster and i think the cracked version should be fine).