The 18" unit is just the right size for the 14" project boards we use in our carvers,
plus there's no limit to the height/thickness of the stock or item you can run across the drum
so it does a great job as a straight edge sander as well as a flat surface sander.
See if you can find a few more written reviewers about them, before you decide which type of sander to buy.
Their rather pricey, but are built stone solid and are close to the weight of the CW Machine, (also their quite easy it learn to use).
"and that's a helpful feature for folks like me"
Ken
Ver 1.182 on XL Pro plus Ver 1.164 and 1.175 on Windows 7 Ultimate
It Never Fails * Till * You Say It Never Fails