SQ: Is RSA Tomahawk = RSA Predator with IEMs (analog)?

Keep it. It just get better the more you listen to it. I hooked it up to the Alien DAC to my computer. DUDE They rock together. Cheap upgrade.

Yes, the Predator does offer better SQ than the Tomahawk, with more output power to better drive demanding phones as well as IEMs. I have Hornet, Tomahawk and Portaphile Maxxed -- and love them all -- but use my Tomahawk most often for portability with my Westone ES2 IEMs, and listening to a 1000+ hour Predator loaner -- now around 1200+, the Predator has (with my ES2s as well as K701, DT880 and HD600) more authority, weight, LF energy/drive, better timbre and imaging, and seems even a bit cleaner and transparent than my well-played Tomahawk (don't know how many hours on my TH, but certain well over 2000).

That said, I wouldn't say the difference is staggering, but it's there and readily audible -- as long as one does not judge it at early stages -- which for this amp means many more hours than even the Tomahawk (which took about 600 hours to mature). If you read the jamato8 "blog" on the progress of his Predator, you'll get a sense of it's character.

I briefly had both this 1000+ Predator and a 400-hour Predator, and the younger one had immediately apparent deficiencies compared to the mature one -- so great patience is an absolute requirement. Faith is not necessary, since you'll read a goodly number of posted testimonials to the wonderful sound of the Predator, once it has matured. Since I got this one with 1000+ hours already clocked, I don't personally know when the apparent turning point is, but it seems to still be improving somewhat. (I'm sure someone will throw a "psychoacoustic" dart at me for that, but it's to be expected here when you stick you're neck out -- so to speak.)

...And, of course, the Predator has a very nice DAC included.