• First, let me just say I have been rather busy lately getting some extra work time in before vacation. Sorry I didn't get a quick reply to you.
• Second, there was never a Golden Sabre II Plus. There was a Golden Sabre, then Golden Sabre Plus, then the Golden Sabre II. Only three (3) Golden Sabre models.
• Third, I'll give you my opinion in answer to your question. As another has already replied, a Golden Sabre II (based on the Pantera circuitry) had the ED-120 discrimination similar to the Silver Sabre II and Bandido & Bandido II. With those models, when set at the minimum discriminate level, you have very good iron nail trash rejection.
The Bandido II µMAX also has an ED-120 discrimination, but due to the low-noise/high-gain circuitry it is noisier in densly iron trashed sites than the other models mentioned, and doesn't do quite as well in dense iron junk.
The Eldorado has an ED-180 discrimination circuit and due to the lower adjustment range it will provide better punch in highly mineralized ground at the minimum setting compared with any of the others mentioned. The trade-off, however, is that even if you increase the discriminate level you don't even get as clean a rejection on iron trash as you do with the Bandido II µMAX!
So, if you are hunting a very trashy site with a lot of iron, such as the old railroad ghost towns I frequent, then my pick would be the Bandido, Bandido II, Silver Sabre II and then the Pantera/Golden Sabre II.
If hunting common sites and wanting 'OK' trash rejection, but not needing an all metal accept discriminate mode, the Bandido II µMAX is tough to beat.
If you hunt black sand, very mineralized fresh water beaches, for example, and/or you just want all metal accept discrimiation, the Eldorado is the way to go.
Now, back to your new acquisition. As I read your follow-up post you clarified that the unit you are getting is a Golden Sabre Plus. These were very good models with similar control adjustments and dual-tone audio capability as the Golden Sabre II, but they were the offering before the introduction of the ED-120 discrimination. Thus, the Golden Sabre Plus lacks the expanded lower-end discriminate adjustment. It will hunt quiet in iron trash, but because there is so much bias to the iron, masking can be a problem in nasty conditions.
While the Golden Sabre Plus will share the common search coils as the others, it was unique in that it was listed as having a higher operating frequency (15 kHz) than any other Tesoro prior to the Lobo/Lobo ST/Tejón.
The Golden Sabre & Golden Sabre Plus had a good audio 'bark,' but I will say this about the Golden Sabre II, Pantera, and many earlier, pre-µMAX Tesoro's: They suffered much more from inconsistent performance. There were too many 'hot' and 'cold' specimens of the same model.
Hopefully, for that good price you will have a decent, good working Tesoro !
<EM><STRONG>Monte