Well Intrabolic, what i currently use is the top of the top in terms of intra-work supplimentation. Mostly because you get 15g of Aminos, more then enough,It has whey hydrosalate (sp?) 70-80% di and tri peptides which equals that of peptopro which is 80% di and tri peptides. Also whey hydro has more studies behind and has a better amino acid profile then casien hydro. Not only that but di and tri peptides absorb faster then free form amino acids themselves, there is even some research suggesting that the di and tri peptides help free form aminos to absorb even faster! Next it has electrolytes, 3.2g of beta-alanine! almost the 4g which has soon weight gain and endurence in studies. Not only that but beta-alanine is the second most studied ingredient in sports nutrition today, second to only creatine mono. Then they have 8g of free form EAAs with high levels of leucine, 3g is needed to spike protein synthesis AND all the EAAs are needed to create the best protein synthesis response from leucine which intrabolic has. Also it say 2.5g of leucine per serving but with the whey hydro is actually 3g total. It also requires very little digestion so it reachs the muscles better, also intra-wo amino supplimentation has been shown to increase amino uptake to the target muscles up to 500% i believe. There is more but thats the basics.
The new size on is not has good as intrabolic in some regards, Its whey hydro is only 50% di and tri peptides, meaning more digestion on your part and more blood to the stomach, not what you want around/during your workout. Next it has no beta-alanine, but does have a matrix of creapure and MCC, which is a very good combo, but if you dont want 4g creatine during your workout then size on doesnt work since you cant adjust it. Also it doesnt have all you free form EAAs it only has 10g 2:1:1 ration bcaa in it for the leucine content. Still good tho. Also the LOLA is to low to matter since i believe several grams was shown to be effective at removing amonia not the 1-2g they, think more like 9g needed. Then the sustamine is to low to since it fall behind some electrolytes, and sustamine needs to be in a 3g serving to really matter. Then they have a carb blend, palantinose is an awsome carb and the main one, however it is 50% fructose and 50% glucose, you could do without the fructose intra-wo, also 38g sugar is harsh and empty calories, id save the carbs for meals but i did notice good effects from the carb version of size on and the repartioning agent works quite well actually, just got bloated from the low grade hydro, slow carbs, and creatine after awhile, the flavor was to much also.
In the end id give the nod to intrabolic for intra-wo supplementation, everything you need and nothing you dont, the flavoring of wild berry is nice too, personally if price is a factor id go with purple wraath, since its an EAA product and has a nice nootropic effect if you havent tried it, or 1 scoop intrabolic with bulk bcaa.
Hope this helped
EDIT:Also Intrabolic and all AEN products are manufactured in GMP certified facilities which are the highest quality standards in supplements, it means whats on the lable is in the bottle pretty much. Also Gaspari does not have this on their products and they had that issue with their myofusion not being 25g per scoop. Idk if this matters to you when picking a supplement but thought i would add it, Controlled Labs is GMP certified as well