lol took me 15 min to read all the comments , as Gaurav very well handled this thread by giving valuable suggestions , Lumia 720 has better camera when compared to Lumia 820/1320 since 720 rear camera uses a fast lens at f/1.9 which enables low-light photography and creating bokeh in the out-of-focus areas of an image , but it can not record full 1080 p video , front camera on 720 is a 1.3 MP(720p HD camera same as Lumia 920/925/1020/1520) , hardware wise 720 has s4 dual core krait processor with adreno 305 GPU , 512 ram , 8GB flash storage(SD card support available upto 64 GB) , battery is same as Lumia 920 , better battery life due to non HD display(it's a WVGA clear black 780X800 , making it 217 ppi covered with corning gorilla glass 2 coating ), now lets compare it with second competitor Lumia 820. it was launched alongside Lumia 920 , it has faster processor with better GPU adreno 225 found on Lumia 920/925 , 4.3 AMOLED clear Black 800?480 , better screen resolution when compared to Lumia 720 , 1 gb ram , faster processor & GPU are advantages of buying Lumia 820 , but disadvantages are very clear , 8mp camera is not as great as 6.7 on Lumia 720 , don't count MP , the sensor on Lumia 720 is better in picture quality and with f/1.9 , 720 sines in low light photography , but some games requires 1 gb ram so 720 lacks extra ram , its not yet clear what features of windows phone 8.1 will be avliable for 512mb devices , its a wise decision to invest in 1 gb phones since all flagship phones have it , so chances are high they will get more features as ,(sudden change in Lumia 520/525 ? Lumia 525 will get more features in this segment) , back on comparison Lumia 820 has a low capacity battery , if you are a power user , keep a charger / extra battery ready .Lumia 720 clearly wins in battery due to lower spec/low power consumption. now lastly Lumia 1320 (phablet ) if you are comfortable with 6"inch phones , (I love big phones
) it has pure motion hd+ display one found on Lumia 920/925/1020 , its actually better than any other 720p display , you also get a extra 3rd row column , which takes advantage of huge canvas on 1320 , on specification Lumia 1320 has the fastest processor on any Lumia(forget Lumia 1520 it has latest sd 800) , 1.7ghz dual core processor, GPU is adreno 305(one found on Lumia 720 ) and 1gb ram , 8gb flash storage and SD card support , battery is also one of the best out when comared to Lumia 720,820(lol seriously 820 ),920,925,1020 , 3400 mah battery is just (I always wanted on this high capacity in my Lumia 920) , it can easily run any games/applications with great display/battery life , 6"screen makes it easier for one to pin more tiles ..less scrolling to fin fav apps.1320 lacks in camera section just a basic 5mp shooter camera with flash , but the results are not that bad , its the same quality one get from Lumia 625, oh yes it can record 1080p video , but the front camera is just 0.3 VGA camera , same for Lumia 820 but Lumia 820 can record full hd videos too I forget this point above, this is going to be a huge post , quickly saying it's a wise decision to invest in 1gb phones as they wont lack features since Lumia 925 is still a 9X flagship phone by nokia , its quiet sure 1Gb ram phones will get better apps, update features by nokia/Microsoft in coming months ) , so Lumia 1320 is my opinion or if you like taking photos buy Lumia 720, 820 is good in hardware but poor in battery life.