Hi there Panzerfist
I've got about a 1/2 dozen Kagero aviation unit histories - including 2 volumes on JG1.
I really like them. The bi-lingual text is well written and there are plenty of useful photos, backed up by excellent artwork.
Some of the books have small etched-metal frets or bookmarks with colour samples on, but I tend to go for volumes with decal sheets, which offer some very attractive schemes. These are printed by Techmod and are excellent quality, although a little care is needed applying them.
If you go to the Reviews section and type Kagero in the "Jump to MFG/Vendor" window, you'll find reviews of several titles.
Hope this helps
Rowan