Smd definetly adds some challenge
for example its 10 easier to route and fit components with a 328 dip, than a smd version
in the dip I can pit the crystal,caps, and a few resistors under the socket, and never have a problem runninft traces, with tthe smd and the same components take up. More space
and I usually cramn it all and make it fit then run traces , alot harder with smd