I asked this same question about a month and a half ago. Ultimately I decided to go with a new dp24. (From reputable ebay seller for $430.00+free shipping)
Reasons being:
1. You can buy it brand new so you'll get a warranty/return....Can only find used Neos in various conditions.
2. Firmware updates; Tascam adds new features and fixes bugs with firmware updates...I dont think there are anymore firmware updates for any 2488s
3. Color screen.
4. Records on removable SD cards instead of internal hard drive.
These were my selling points. Good luck with whatever you end up choosing.