Parler is similar to speak to (in the sense of appeal to) in that case.
to be interesting or attractive : APPEAL
- great music … speaks directly to the emotions — A. N. Whitehead
(Merriam Webster - speak 3.c)
Choisissez la méthode qui vous réussit le mieux
implies that you've tested the method before and have had some success with it. Parler implies the opposite. Ce qui vous parle is what appeals to you at first sight, on a first impression as opposed to a tested and proven option.
Choisissez la méthode qui vous convient le mieux
(that suits you best) could be interpreted both ways but is more likely to express effective suitability than a simple feeling.