The screen is not too big and a bit grainy with 3.5 inches. Since I do not intend to surf so that's not so important. Runtastic is running so fast and can be operated very well. GPS is fast and accurate. Quick check an email or listen to music at the same time are not a problem. The processor is more than adequate. The memory seems sufficient for all my standard apps I have installed on my LG G2 also. For music I have a miniSD card inserted.
Those looking for a compact smartphone gets here really a lot for your money.