Pure raw performance wise Lumia 525 >S Duos 2> Moto E
S Duos 2 has cortex A9 dual core & the GPU isn't bad(it's the same chipset as that of S2 Plus). It's a good buy for 8.5k, but you may never get an Android upgrade. You get a decent enough camera with flash & front facing camera
Moto E may be better in benchmarks due to kitkat. It will get future Android upgrade. Its a vfm phone @ 7k.
I disagree my friend Here.. you might be unaware that the performance of Cores doesn't stay static .. Arm generally Updates and modifies the Performance of Cores during the period of time..
The Cortex A9 used by Broadcomm are the weakest Cortex A9's and are of older generation . But the Cortex A7 here is a updated and newer Cortex A7 which gives out more performance than those older A9. Compare Mediatek 6589 vs 6582 Cpu even though technically both are Cortex A7 but you can see the newer cortex A7 in 6582 gives out more performance due to it being updated and revised version it is r0P3 . Qualcomm did not have old Cortex A7 CPU till last year so they are directly using the newer Cortex A7 .
The newer and updated Cortex A9 are Revision 4 Cpu and currently they are available only in Tegra 4i . s duos 2 is also on 40 nm and Moto E is on 28 nm so they are power efficient as well..
That's the reason it is performing better than S duos 2 in benchmarks.. An OS upgrade can help in eak out more performance in IO, Ram management, and other overall Complete benchmarks such as Antutu and quadrant and to some extent GPU benchmarks but i doubt a CPU intensive benchmark would benefit from it and even then an Os update can only bring around 5-10 % performance at most that is the general case so i doubt android 4.4 would help that much in case of S duos 2..
Secondly galaxy S2 Plus itslef was the Downgraded Version of Original S2 which had Exynos which was much much more powerful than any CPU at that time.. Exynos was even Much better than Snapdragon Scorpion Core at that time and people in the USA use to feel jealous that they did not have exynos in their phones.. Now the situation is completely opposite People Demand Qualcomm and avoid Exynos . that is why S2 plus was a flop phone
and yes the GPU sucks . Moto E performs approx 2x or 100% better than Videocore GPU and don't forget the driver support..
But like i said in previous Post Moto E is being reported to have lag in Asphalt 8 which shouldn't be happening at all. but still i will hold that S duos 2 is still quite inferior than Moto E..
*gfxbench.com/compare.jsp?benchmark...gl&D2=Samsung+GT-S7582+Galaxy+S+Duos+2&cols=2