My QRH is very straight forward. A "go around, windshear ahead" should be responded with a windshear escape manuever, or at pilot's discretion, a normal go-around. You really want to gain as much altitude as you can and start turning away from the warning area, which will be displayed on your ND, before you get there. You might be descending quite a lot in a severe windshear even with engines firewalled.
The only time I would consider ignoring it, would be in nice weather with light winds and no convective activity whatsoever. PWS has been known to produce some false warnings on airports next to large areas of water. But having a CB on upwind... I'm hitting that TOGA and getting out of there.