Toxic is very niche and generally only used in specific clan boss teams. 

Lifesteal is viable in a lot of different content, so definitely lifesteal. 

But, as mentioned the last time you asked - set bonuses should not be a priority for you. They're icing on the cake. Focus on primary stats/substats.

i know and im working on maxing masteries after that they are maxed. i wasnt asking to see which i should use i know my opinion and was just curious to everyone elses

Agree on stats vs. sets, still good to figure out what kind of sets you should be saving for later, though. 

im confused i why i shouldnt worry about gear yet to grind stats if i can combine the 2 by farming dragon keep like crazy. even if i should focus on stats no matter what level player u r gear could turn the tables

We never said don't worry about gear. We said don't worry about *sets*.

Set bonuses are nice, but they are far less important than the stats on the items themselves. Your goal should be to make sure you're using at least 5* epic gear in all of your item slots, with at least 2 substat rolls on a "good" substat. Which substats are "good" are dependent on the champ in question. Speed, Crit Rate, Crit Damage, and Accuracy are almost always good for everyone. The other stats are specific to the question - ATK champs want ATK%, DEF champs want DEF%, etc.

So, for example, for a champ that is ATK based - for example, Ninja - you'll want to aim for Crit Rate gloves (eventually crit damage, but you won't have enough crit rate from substats for now), ATK% chest, Speed boots, ATK ring, Crit Damage % amulet, and Accuracy Banner.

lifesteal is very useful early-mid game in CB, and other areas as well.  A lot of players auto sell toxic.  I try to keep the best few pieces of toxic I come across, but lifesteal is worth much more in most situations.

of the two, lifesteal is better, but neither are all that great. toxic is considered one of the worst sets in the game and for good reason; it's awful. it confers minimal benefits at a cost of a majority artifact slots. lifesteal is better in every area of the game, but it's best used in the early game when you have a limited selection of champions or the very late game when you're building champions for extremely niche areas. between the two, it can be pretty helpful on glass cannons, but on the whole, you'll generally achieve more with a team of four champions built for damage output and a decent healer than you will with five champions in lifesteal sets.

I found having a strong lifesteal set (or two) to be extremely helpful in finishing off some FW20-21s. 

well i disagree tho it may not offer much stat benifits, poisoning your enimy can be very useful especially when you have the toxic set equiped on more than one champ. life steal is also great because it heals you when you attack so i have that equiped to the champ i need alive the longest then i have 3 champs with toxic and the one that i need alot of accuracy on has 6 peices of perception gear.

i dont have a healer yet so until i get a good healer i have to crawl my way through the game 

life steal ,definitely a set that helps you everywhere, if you don't have an unkill team at the boss clan without life steal it doesn't work 

Most people run Leech instead of lifesteal gear for CB. Much easier to gear around.

Of course, they are also much easier to remove than craft items 

Lifesteal  gear  is  considered better  vs.  Toxic  gear.

However,  I  always  like  keeping a  few  pieces  of  every  gear  set  in  the  game.

I  do  it  incase  the  game  decides  to  buff  the  set.

Sometimes,  Sets  which  are  considered  bad  can  become  very  strong  if  they  get  buffed  or  if  the  game  releases  new  content  which  makes  the  specific set  shine.

Regeneration  gear  use  to  be  a  bad  set.

The  game  buffed  the  set  to  give  it  more  healing.

After  the  buff,  The  Regeneration  set  became  very  popular.

It  is  used  alot  in  Faction  Wars  &  Speed  Dungeon  runs.

Destroy  gear  use  to  be  a  bad  set.

The  game  released  a  Doom  Tower  Boss  named  (Scarab  King).

After  the  release  of  the  Scarab  King,  The  Destroy  set  became  very  popular.

It  helped  counter  that  Boss  fight.

So  you  can  see  why  I  like  to  keep  a  few  sets  around.

Yeah I Like to store some of each too but what I Keep equiped is Toxic and a 2 piece set that gives shield buff on half my team and my champs that I need around longer I have life steal and a 2 piece set that gives shield