AWS officially recommends CNAME records for ELBs, but the IP addresses don't change regularly and also CNAME for root host name won't work if other records are present, so many sysadmins straightaway use A records with the ELB IPs.
Considering most active domains have MX records under the root host name (like example.com.), CNAMEs won't work for these hostnames.
If there's native implementation for an "ALIAS" record which only points to the corresponding A record of the target, then it will work anywhere.
This is only true if you have a stable level of traffic, IIRC. If they have to scale the ELB up or down the IPs will change.