Full Guthan's: Is it worth the 7m?

[Xeones]

If I made enough money to afford full Guthan's, would it be worth it?

 

 

 

In terms of training Slayer while training Combat stats.

 

 

 

I would be wearing Black Mask, Fighter Torso, Dragon Platelegs, and Rune defender while training and take out full Guthan's when I'm at 33% Health.

 

 

 

But is it worth it? Because many Slayer tasks require that you wear an item that renders the set effect useless, such as a Facemask while fighting Dust Devils.

 

 

 

Also, would using full Guthan's be practical when killing monsters for pure profit? Such as Bloodvelds for the Blood runes they drop?

 

 

 

Finally, about how often does the set effect kick in? I don't want to take out full Guthan's at 33% Health for the set effect not to kick in and I keep losing Health to the point of running away.

 

 

 

Thanks in advance!!!