if you have relatively low stock gears then up to 1" more is usualy possible without too much draw back.
There are also the cases where you extend your axle ratio so much that you exactly lose one gear and you have then 2-6 instead of 1-5. It happened to a feriend and although starting is a PITA, once rolling, its .... sort of ok ...
Otherwise I 100% agree with you.
Matt