hello guys, i wanna ask on how u guys think which one should i get out of these 3. They have similar specification and price.

Dell Inspiron 15-5000, i5-4210U + Radeon R7 M265(GDDR3) @RM2399, 4GB, 500GB, W8.1 (1366x768)
Asus K551LN, i5-4200U + Nvidia GT 840M(GDDR3) @RM2399, 4GB, 1TB, W8.1 (1366x768)
Lenovo Z50-70, i5-4210U + Nvidia GT 840M(GDDR3) @RM2299, 4GB, 1TB, W8.1 (1920x1080) <-- im leaning towards this

i use laptop mainly for my uni (bring to class/library for assignments) so battery life and mobility is much needed. Maybe u guys would recommend me Dell ultrabook Vostro 5470 for this, however, i saw so many complaint about its wifi (Apparently, the lower plastic chasing of Vostro gimped the wifi antenna capability). But, well, i think as it is lower than 2.5 kg i think its should be acceptable (i wouldnt mind exercising my back & shoulders muscle too carrying it in my backpack to uni back and forth haha). Also, these 3 has a haswell processor, which (correct me if i'm wrong) guarantee 4 hrs of battery life under casual use.

Also, i will use this laptop for my home entertainment too (mainly casual gaming, music, movies) so i choose rather discrete graphic cards and i5 for this purpose. My games that i played would be mainly minecraft and dota, and some old offline games.

I also like the detachable batteries to keep the battery lifespan much longer because i mainly use AC adapter on my home, and gaming will increase the temperature of my laptop, which is bad for non-detachable li-ion battery lifespan (one more reason to not choosing Vostro 5470). Even though Dell and Lenovo have the software to limit the battery charge below 100% (and disable battery charging when on AC) for the best battery health, i feel like non-detachable battery still get the heat effect from the laptop after prolonged session of gaming.

Thanks in advance