Honestly, Slugga Boyz are still fine as they are. Do some Mathhammer and you'll find out that, as long as you play them right, Slugga Boyz are just as good as Shoota Boyz. The only advantage does come if you consistently play against stuff with a 5+ Armour Save. Against such things, Shoota Boyz gain the edge. But its not a large enough edge to mean you should waste those cheap
AoBR guys.
However, what is not as good in 6th is footslogging Boyz. The 'remove from the front' rule and Overwatch mean that your opponent will likely be able to get an extra turn of shooting in. It's still viable, I guess, though I wouldn't really know because I haven't ever ran a Tide, but you'd certainly need a
KFF.
Despite what people tell you, a
KFF is still mighty useful.
Finally, what DacGerm has said about Ghaz and Deffkopta is very true. So bear those points in mind as well and you should be well on your way to making a good list