Both cannot be equally judged (sorta) as they are particularly two different tanks. But they do lay pie plats ^.^.
Whirlwinds have flebility between mines and missiles, though I only have use the missiles as choice.. It is a very cheap, and effective tank to use against hording armies. It is actually a very valuable piece to my army.
Vindicator, very short ranged, but packs a greater punch, but that punch is only needed against power armoured foes or such.. and those foes are just like you, and have a good chance to kill that tank. But it is does bring it a serious fear magnet to foes, if you want that.
depends what your purpose for it really, they are both good tanks