Eh, they're alright I guess. I still prefer my poisoned attack witches, keeping them alive with a 5+ Ward is still practically the same as a 5+ AS in CC. Different units, different jobs, the points limit will also dictate which is better, since it will dictate how many monsters or light infantry the enemy will field.

but again you have to think, the corsairs are core and thus go towards your minimum core choices. and if they can ALMOST do what a witch can do and leave me room for other specials then more power to em. not sure but did they change the no penalty to RhB stand and shoot?

Thats how I've been using them as well (without guiding eye character). It has worked pretty decently so far.

I run the unit at 30 (10x3) with the sea serpent standard

If you move the unit into range it will get 42 shots hitting on 4+, then when the enemy charges you get 42 more shots hitting on a 5+, and then 41 re-rolling to hit attacks usually before the enemy can strike due to higher I.

According to maths against a t3 unit with a 5+ save you should do at least 20 wounds before they even strike a blow. And with so many dice being thrown there is potential for many more. This means you can pretty much wipe out an elite t3 unit eg. swordmasters or black guard or you will remove at least the last 2 ranks of a larger unit probably removing steadfast)

plus there are many available synergies with spells. If you have a nearby sorceress casting soulblight then the carnage massively increases. Or what if you made those 41 re-rolling attacks s8 with Okkams mindrazor

It has done pretty well for me so far
- units with 10 wounds or less eg. fleshounds, knights may as well not bother going near it as they will get raeped
-light infantry units get torn up by it
-with flame banner it has blatted an Abomination in one go

What it isn't good against is large units of tough and well armoured troops like chaos warriors. They will run in laughing as the bolts patter off them like rain and then will tear your corsairs to shreds.

-Also having frenzy means there is a tiny chance the unit will rush into combat without you getting to fire at all. This has never happened to me when the unit has been near the general and BSB. It did happen once when they were out of range however and caused them to get creamed by a large halberdier block. I like the 10 extra attacks but some people might see this as an unacceptable risk and take AP banner or flame banner instead.

I actually like blocks of corsairs with handxbows. I use 3 ranks of 6, and find that they work great as anchor units. They roll up, shoot at the foe, then are ready to shoot again when the foe charges and likely strike first with their I5.

Sure they're not a game-breaker, but 2 opportunities of handxbow fire can really whittle a foe's unit down, especially light infantry.

Anyhow, that's my thoughts.

Cheers.