airplay is basically just network traffic, and switching to apple won't necessarily make it work better. I would look at the health of your existing network before just jumping to an airport express. It sounds like you have a weak signal or interference from other sources. and an express won't fix that.
The express's wireless coverage isn't as good as some of the other branded routers on the market.
Which netgear router do you have?
take a look for WMM settings, change to the other setting. Might fix it might not.
if you're using the 2.4GHz band, there are several things that can interfere.
--Cordless phones, baby monitors, microwave ovens (when cooking). - try unplugging them and see if it fixes the problem.
If there are other networks in your area, they can interfere...
- alt-click on the wifi logo in the menu bar of your mac.
Select wireless diagnostics
don't Click continue go to the menu and select "window -> utilities"
select the wifi scan, and hit scan now
it will tell you the best channel to select to avoid interference.