The A400 totally out-performed its price-point at the time, and the biggest shortfall was the fact that the price lead many people to pair it with sources and speakers that just weren't good enough for it. With a very good source and the best speakers you can get, it will perform superbly.
I've had systems based around 3 different A400s over the years. A particularly memorable one was with a Marantz CD63MkII KI Signature and a pair of Quad 11Ls, but it sounds even better with the Apollo-R and Dynaudios. I've been listening to music all afternoon and I haven't felt any draw towards putting the Pioneer away and bringing the Brio-R back into the system. Music has included Mahler, Bloch, Nick Drake, Nancy Kerr, Efterklang, and the new albums from Spock's Beard and A-Ha and it has all been hugely enjoyable and involving. Not a hint of being clinical or grainy, just sheer involvement and musicality with a particular talent for conveying the tonal qualities of different instruments and voices, and for really showing the differences in production between recordings.
The A400 is unlikely to let you down unless you let it down with ancillaries that aren't up to the job. Having said that, if you want to spend your budget and buy something new have fun exploring some of the options suggested above. PP's suggestion is good if you can achieve it - take an A400 along to auditions for comparison.