the 40 sizes are great flying planes and come with the retracts already assembled, which is a great + in my book. overall a great selection. kyosho and CMP also make 40 (50) size planes but are fixed gear. the Kyosho is more detailed and "scale" than the WM but i'm not too fond of the covering scheme. the CMP is much more scale than both but the fiberglass fuse is heavier and more difficult to work with.

VQ also makes a P-51D as well as the more rare P-51B. I beleive they also come with retracts but not installed (at least mine weren't) the planes are decent but the covering is cheap though well detailed.

overall the WM is the best choice for a beginner/intermediate since it offers superb flying characteristics, easy assembly and easy to repair. it may not be the most scale (CMP takes that) but it does look good and is well made.