BGA REWORK- IR OR HOT AIR CONVECTION ? IS THE BEST

1.which type of rework station is best compare to the IR or HOT air convection?
2.Which process plays best reliabilty on soldering after post soldering process?

For small boards simple components (low mass, dark colors, etc), IR can be of good help.
Forced hot air works much better and in a reliable way. According to the configuration (ie.high power bottom heaters, etc) you can remove/replace large and heavy components (ie. BGA, even CCGA 52.5 mm x 52.5 mm >150 grams)on a very thik board (> 3,5 mm)( we did it by DRS-24).
Hot air is best. IR takes longer and is affected by the color of the part.