I own 又一居 (786 sq ft) and my brother owns a 900+ sq ft 麗港城, so here are my comments:
又一居 - 保值,抗跌力高. But 700 sq ft is much smaller than 900 sq ft 麗港城. Very convenient as can walk to MTR. Even if your block is further, can still take mini van to MTR (only 2 min wait). Mgt fee is high ($1.8 or 2.2 per st ft depends on which block you buy). Floor plan much better than 麗港城, so easier to fit in furniture. Environment is very good. Most outside view not good, so quite dim inside.
麗港城 - not 保值, many blocks are very inconvenient, only a few blocks are quite near to MTR. Mgt fee is cheap ($900+). Overall the view is better than 又一居, but environment not as good.
Neighbourhood in 又一居 is very good, security is also very good.
The grade of 麗港城 and 又一居 is different, because 又一居 is in a prime and higher class location.
If you have less family members, I will definitely choose 又一居. Anyway, I see that many families have 5 members living in a 700+ sq ft 又一居 without any problem.
If you choose 又一居, please choose the block nearer to MTR, as easier to sell. Block 20+ are not as easy to sell during economy downturn.