Well these rides cant be compared because both belong to different categories. But still if you want to dig out some advantages and disadvantages than let me put few of them here:
Advantages of Altis S/R over GLI:
1) You have a stronger engine abviously because its a bigger one in the same line up. As both engines are towing same sized body, the pick and speed increases.
2) You will have a fuel cut system which will increase your safety in case of any crash.
3) You will get body colored mud guards.
4) You will get alloy RIMs.
5) You will get sun roof.
6) You will get leather packaged seat covers.
7) You will get adjustable tilt steering wheel.
8) You will get better information displays at panel.
9) You will get driver side SRS Airbag.
Disadvantages of Altis S/R over GLI:
1) Obviously Altis costs more
2) Altis drinks a lot more fuel and that is obvious too.
But I will say again. You cannot compare these cars as both belong to different categories.
Best of luck in your upgrade.