One thing I feel csgo did really well is making more guns valuable. In 1.6 the only pistol really worth buying was the deagle. The 5-7 (and T berettas) cost 800 bucks so it was more of a novelty to buy. p228 was pointless whereas the p250 is commonly bought in GO. by othe USP and glock were perfectly viable pistols even in eco rounds (subjective based on your experience and skill of course)
mp5 navy was such a good smg (at $1500) that generally, no one really bought the mac, tmp, or ump except for novelty. though you could get some pretty nice close-mid range burst kills with the tmp/mac. in GO you see a lot of umps and bizons. by contrast the mp7 is horrible
rifles - in 1.6, no silenced variant that you had to equip. you just had the m4a1 that you could silence or unsilence. silencer modifies accuracy and damage.
mp5 navy was such a good smg (at $1500) that generally, no one really bought the mac, tmp, or ump except for novelty. though you could get some pretty nice close-mid range burst kills with the tmp/mac. in GO you see a lot of umps and bizons. by contrast the mp7 is horrible
rifles - in 1.6, no silenced variant that you had to equip. you just had the m4a1 that you could silence or unsilence. silencer modifies accuracy and damage.