I also think its a development with many upsides. But I'm also concerned about capital appreciation. I just posted a separate reply on this in another fourth avenue thread before seeing this thread. Unfortunately, I'm a newbie and can't repost the link to that thread here. So I'm regurgitating what I posted before here, hopefully it doesn't contravene any guidelines.
The psf has dropped since launch day (now around 22XX - 23XX) and its quite close to breakeven cost (about $2100 ++) from what I hear from agents. So it seems that buying in now is safe because the prices unlikely to go any lower - if anything it would go higher nearing TOP.
Looking at CCR prices condo launch prices right now, PSF can be as high as 26XX - 30XX such as the launches in Holland V and River Valley area. Yet, CCR prices are considered fairly suppressed right now based on UA price index - so prices will only get higher once economy recovers.
As for rental, there isn't any condos with one bedders at Sixth Avenue. For that matter, there is only fifth and sixth avenue residences there which are small developments with less and older facilities so there really isn't much options if anyone is looking to stay here (whether it is 1, 2 or 3 beds). There are condos along KAP, Tan KAh Kee, Botanical Gardens and Stevens Road and a check on property guru shows that 1 bed units are not many available for rental. Rental transactions for these condos are also quite healthy which indicates demand.
If purchasing 2-3 bedrooms for own stay, then there is also RoyalGreen but it's definitely more pricey (around 26XX-27XX psf). While there is argument that those who are rich will choose freehold over leasehold, but there is always another group of aspiring owners who wish to stay in this prestigious area but are unable to afford the FH pricing (and may prefer to commute by MRT because of it being at doorstep and leads straight to CBD or One north within 15-20 min). Across the road, there is a couple of plots that has been designated as residential (the whole turf city area which is hugeee, and a small plot directly opp Fourth Avenue) and are in D11. These are unlikely to be opened for bids in the next few years so supply will be limited once RoyalGreen and Fourth Avenue is sold out. And even then, these plots won't be as near to the amenities (which I think is really good - many local eateries with decent pricing, restaurants, banks, medical and dental clinics), and not as close to the MRT.
While the above seems to be big advantages of fourth avenue, my biggest gripe is whether there is future capital appreciation. It is not very near to the Bt Timah Transformation - even the sky park that will be built is 10 mins by foot from Fourth Avenue. I don't forsee any ripple effects from the changes at Beauty World either. Even if Beauty World Centre or Bt Timah shopping centre/plaza is revamped into good size shopping centres, it is still two MRTs away. And the Grandstand is not really a good shopping mall though they offer daily shuttle service from sixth avenue bus stop. It may very well be demolished anyway since it is in the Turf City area slated for residential. But capital appreciation is likely to happen if the lands opposite are released for condo launches - it is quite certain that land prices will only be higher, which translates to high launch prices. But this would be in the long term and even then there is some uncertainty. Also, rental yield likely to be lower despite the potential demand due to higher quantum but then rental yield in CCR is typically below 3.
If you are buying for own stay, I suppose capital appreciation would be secondary. But I think this should also be part of your consideration if this won't be your forever home.
Above is my two cents worth on buying for own stay and investment. Frankly, I am quite divided as well although I do see some upsides for this property.
Hope to hear from the rest!