The Valley
I will only comment on FV as this is what I am more familiar with. Bear in mind I'm from Sydney so I'm looking at things clinically.
I'd divide FV into the following zones;
1) The sleazy bit (the bit mainly along Brunswick between Wickham and St Pauls Tce).
2) The bit that feels like a wasteland to me (bounded by Gregory Tce, Brookes St, Bowen Bridge Rd and Wickham St).
3) The genuinely cool bits - typically along James St towards New Farm and the streets bordering New Farm.
4) High rise areas - typically along Ann St from Commercial Rd back towards the CBD
5) The Emporium mixed use precinct
There is a lot of supply coming in zones 1, 2 and 4. The upside of this is the gentrification that is occurring - particularly around the RNA. The downside is the potential for poor CG due to oversupply.
Zone 5 is an odd area, it may in fact be the development that triggered the gentrification of the Valley (I can't remember). It has been popular and has arguably Brisbane's best boutique Hotel (The Emporium). I think there is a risk this area will be overshadowed by Gasworks, RNA and James St, however I think it should remain popular with tenants (just not sure about CG).
Zone 3 feels completely different to all of the other areas, you might as well be in a different suburb. I think supply is more constrained in this zone due to council land use rules.
As to whether I would rate FV as a 1 or a 5, it is not that simple. A $400k 1B in zone 2 doesn't compare well to an equivalent product in the better areas that will set you back $430-$450k.
If you are considering FV you should take a look at Teneriffe, Newstead and New Farm as well.
If you are serious, get up there and walk around the place, you will see what I mean when you get there.
I should also apologise to Brisvegans if I have disrespected their territory
Trev