Although PolarBear's response wasn't too helpful to you, you haven't really given us much to go on in order to help you. The SAM stuff is great as is the Sonic Implants stuff. To say one is better than the other probably does not paint an accurate picture. They both sound great but have some slight differences and features.
SAM Solo Sessions has what looks to be great solo brass instruments for a great price. But, it is only solo instruments. When you need to have multiple horns playing a unison line, stacking the same samples on top of each other will not achieve the same result. Going for the entire SAM bundle will provide you with some great ensembles as well as solo instruments. ProjectSAM has a bundle price which is nearly half price of the SIBrass set.
I own all of the SAM ensemble libraries (but not the Solo Sessions yet) and they are great indeed. I do not own the SIBrass but the demos do sound excellent. The SIBrass has some great flexibility though in the different staccato articulations (ie ta, ka, sfz, etc.) as well as the multiple section sizes. If it is anything like the SIStrings, they have another winner here.
I would say that some of this depends on your budget and some of it depends on which lib's sound you prefer. Listen to the demos closely in order to help. I feel that you can't go wrong with either.
SI has more of a 'raw' sound, and the section sizes are great for creating realistic brass orchestrations (as opposed to playing a four-note chord with a section library sounding like a marching band). It also takes very well to artificial verbs.
Aron that is a really impressive demo! I already have the SI Strings so the Brass would probably be the best choice... I like the sound... However, it was just a pain to get the SISS Library here in Germany!
As far as I know there is no German distributor so I'll have to order directly from SI (like I did before)...
On the other hand I really like the price of SAMSS...
Thanks for the comments. I used VSL and Kirk Hunter Virtuoso Strings - some QLSO for pizzicati and GOS for effects.
I don't have SI strings, but I gather since it's recorded in the same hall as the brass, they probably compliment each other flawlessly. It seems to be generally overlooked, unusual since this is probably one of the most solid brass libraries out there.
Here's link for song witch have been made by SAM set. This clip has "out of the box" sound and only small amount of prosessing has been made to master mix. No reverb or other instruments are inlcuded, but only percussion: www.hallatar.com/teematesti.ogg
Aaron: those strings sounded great! Of course brass was good also.