I'm also looking for a RX solution, battery powered and a fast response time of approx 2ms.
So, what do you mean "fast response time of approx 2ms"? I don't know of a fully powered solution using RFM69 & ATMega328P that has this (depending on what you mean).
From my limited experience, using RFM69 & ATmega328P, you can easily get over two years of battery operation without too much difficulty - if you design your logic to deal with the realities of the HW & SW. Or, you can try to squeeze more out of it and, if you never have a failure or any other devices within RF range, you might get more. However, if you're within a 'noisy' RF environment (ie, there is more than one transmitting node within your network), your best bet is to structure your network to be 'node' driven - ie, the node determines when and if it exchanges data with the GW and, given this, design in whatever 'hooks' you might want to add for OTA SW updates, overriding commands, reconfiguration, etc.
FWIW, Listen Mode on the RFM69 is good for one thing - providing a very reliable, lower power wakeup timer than the 328P WDT. It is worse than useless for long term power savings due to the risks of hangups that drain your battery. Once I learned this, I've switched to low power HW watchdog timers and use Listen Mode as a short term timer as needed.