Top normal or low normal ?

[ricksavery]

I have a 7-speed Shimano Alivio which changes gear (with the thumb part of the shifters) to the easier gear (bigger cog, lower gear).
I think this is low normal. Can anyone confirm this please ? Also can anyone tell me the advantages of a top normal system? The only one I can see is if you hit a hill unexpectedly (?) then it is easier to slam down the gears quickly into a low gear than with a low normal setup.
Got a horrible feeling I am missing the point somewhere
Thanks

 

[HLaB]

According to Sheldon, the high normal double shifts better but the low normal shifts down better. It sounds a much of a muchness

 

[ricksavery]

Thanks for that. According to the link to Sheldon I have a high-normal setup, and I agree, it does seem to be much of a muchness. Can't say that double shifts happen that much (if at all) with me, so no problem with choosing a new deraileur, either type will work. Thanks again