Where I am, east is ok for RGB but there is a refinery with the eternal flame to the north while the west has huge shopping centres and the rest of greater Brisbane plus a brand new brightly lit bus shelter that I can see from the back yard
A lot of the South is lost to me behind rooves but RGB is possible in a few spots.
I do own and have used a Hutech LP filter but the real aim of them is to lower the LP floor to allow for longer exposure times and I did think that it helped with the canon and the qhy8. But since I stopped shooting RGB to the north and west I don't use it, in fact houghy has had it on loan for the last few months.
I've been plugging away at narrowband mainly but it takes so long to get a decent result with all my current scopes that I'm thinking fast newt again. RGB is a lot quicker to achieve a result and it still works ok for me to the east with a small moon.
Here's some examples shot from home :
Helix shot east this week - 5 minute subs - 150 minutes so far. FL-1640 qhy9 (trying for star colour with 5min subs)
Helix shot east in 2008 - 10 minute subs - 9 of - vc200L @ 1250mm - canon 40D and probably an LP filter
leo trio shot north last month, not worth finishing. FL-800 qhy9 - random flaring in all 3 colour channels
So I'll stick with shooting east and do north and south out of town.