I used ball-lock and pin-lock Cornelius and Spartanburg kegs in the past. However, I decided to buy all new AEB kegs when I reentered the hobby after a long hiatus. It doesn't make sense to pay sixty to seventy dollars for beat up old kegs with deteriorated rubber. I used to get kegs that looked almost brand new after a good cleaning for $15.00 each.
I do not find the poppets on the AEB kegs to be a problem. I do not remove the posts when cleaning my kegs. Instead, I fill a keg with cleaning solution after giving it good rinse, push-down on the liquid poppet to allow the tube to fill, and let the lid dangle in the keg with the O-ring loose. I let everything soak for a about fifteen minutes before sealing the keg, hooking up a CO2 cylinder and picnic tap, pressurizing the tank, and bleeding cleaning solution through the picnic tap. I use picnic taps for my kegs; therefore, it is an opportunity to kill two birds with one stone. To rinse, I drain the cleaning solution from the keg, push down on the liquid poppet to allow the tube drain, rinse the keg and lid well, fill the keg with approximately one-half a gallon of clean hot water, affix the lid, hook up a CO2 cylinder and picnic tap, and run the water through the picnic tap. To sanitize, I spray the lid and gasket with Star San solution, pour about a pint of the solution into the keg, rotate the keg to coat all surfaces, hook up the CO2 cylinder and picnic tap, and run the Star San that is in the keg through the picnic tap. My process sounds like a pain in the backside. However, it is easy in practice, and I get a cleaned and sanitized keg and picnic tap out the process.
By the way, a pin punch (or a punch in an arbor press) is the correct tool for removing the poppets on AEB kegs. One wants to push the poppet out.