Much of my own sentiment was already covered here, so I'll keep it short and add a pic.
Boker Magnum = cheap generic catalog knives made in China... Hit or miss much like Schrade, and they should have never stamped the Boker name on them. Rather they should have opened a completely different subsidiary brand under their umbrella...
Boker + = a CRKT equivalent of foreign made knives often based on the designs from designer customs. Still hit or miss, but overall better materials and quality, outsourced through various cost saving countries of origin, although prices often still get jacked up for what you get due to the designer names that get attached.
Boker Arbolito = made in Argentina, (Germany & Argentina have had strong ties ever since ww2). Knives have more attention to detail and quality control is better.
Boker Tree Brand = the original Boker company, made in Germany, best quality of the bunch. Like with most large manufacturers though, lemons do still get through...
I actually inquired with Boker regarding some vintage straight razors I own, (as well as trying to gather more info on Oxford and Morley razors), and as it turns out, it's so hard to find old original information on the old German companies, because many were retrofitted for the war effort, and then subsequently bombed during WWII, and the old files and records were all destroyed and lost. (It's why Boker gets so excited when one of those old documents shows up)...
There is also some connection, be it joint manufacturing collaborations or what, I'm not exactly sure, between Boker and Real Steel as well as Fox knives...
Either way, they do make some quality knives, however they also do have cheap economy crap shoot knives, (and in my experiences their sheaths are crap)... But the 4 I still have I do like...