well beast is way cheaper and its legal. that is 2 of the main advantages. as far as strength gains beastdrol will make you stronger in a faster amount of time. no reason for anyone not to add pounds to their lifts on beastdrol. var is more of a mixed bag if you read peoples opinions on it, some guys say its great, others say they couldn't gain anything even on 100mg. i would say var's advantage is it won't hit you with the sides. like needto said earlier no way could you run tren + beastdrol... they are too strong together. but tren + var is manageable.
i think that beastdrol is a better choice for 'most guys' out there who want to run a 4 weeker and take their lifts to another level..