Barny, I can't find anywhere in mattio's posts that he knocked your $4-$30 filter and personally I agree that its a fine filter. It's generalised backfitting with that filter, its not specific. What me and mattio are getting at is that it would be a less enticing filter if it was $4.75 - $29.56 because you'd backfitted it that way to increase the POT.

Your filters that you've mentioned in your post seem fine Barny, as myself and mattio were both saying (in the general sense) that filters shouldn't be specific down to decimils to increase POT, round numbers or ranges instead of specifics will mean your not backfitting too closely to something that is unlikely to repeat or at least repeat anytime soon.

Anyway I feel like my posts are going around in circles now so that enough from me.