I've always ranked Flower higher. Class batsman, top 4 and carried the side compared to Gilly who played at 7 in a powerful batting lineup. Both have played a lot of great knocks, but Gilly was more likely to flail about or bully a tired bowling attack while Flower had the pressure of always needing to get a score.
Flower also kept for long periods of time as sides racked up big scores against his bowlers, and had to captain a fairly weak team to boot.
While I agree overall, I think the latter point about keeping for long periods fails bigtime since the aussies being a top side would not bat twice every time but bowl twice most times, whereas the zimmers would bat twice and not as often bowl twice so while the zimmers might concede say 600/4d, they would probably not bowl again................................
It is harder to compare the two than you might think. Keeping girly had top bowlers who were more accurate and gave more chances to catch, Flower might only keep once and have a much harder time. Batting wise Flower had the big disadvantage of little batting to support him whereas girly would normally come in with runs on the board and could play freely. That's not to say girly never came in when the aussies were in trouble, but trouble for the aussies was more likely to be 250/5 whereas for the zimmers you're talking 250 all out so Flower would come in much earlier and/or be in much deeper doo-doo. If I recall the match where he spent almost the whole match on the field he came in at something like 31/3 and 73/3 having kept while the opposition made 600+, I doubt girly ever faced that severe a test even if he might have passed.
But you can't tell how girly would have fared had he come in under the same conditions as Flower faced, or if Flower would have scored more runs etc had he batted in an aussie side.
Whether people think girly is better or Flower, can they not just dismiss the comparison because they think whichever is the dogs ballacks.