Neo4j - Specific relationship vs Label - neo4j

Question

[newbie question] I'm kinda in doubt if it's better using specific relationships or labels, but first let me give you a little bit more context.
Suppose that the graph should be able to answer the following questions/queries:
Given a person, return all the emails associated;
Given a person, return all the contacts;
I've come up with these 2 possible models:
They're both able to fulfill the required requests with the following queries:
First model:
MATCH (p:Person {name:"Bob"})-[:REACHABLE_BY]-(e:Email)
RETURN p.name AS Name, e.contact​ AS Contact
MATCH (p:Person {name:"Bob"})-[:REACHABLE_BY]-(c:Contact)
RETURN p.name AS Name, c.contact​ AS Contact
Second model:
MATCH (p:Person {name:"Bob"})-[:REACHABLE_BY_EMAIL]-(c:Contact)
RETURN p.name AS Name, c.contact​ AS Contact
MATCH (p:Person {name:"Bob"})-[:REACHABLE_BY_FAX]-(c:Contact)
RETURN p.name AS Name, c.contact AS Contact
UNION ALL
MATCH (p)-[:REACHABLE_BY_EMAIL]-(c2:Contact)
RETURN p.name AS Name, c2.contact AS Contact
But I'm wondering if there's a best practice to follow in this case. I mean, I know that having specific relationships in some cases is better since we reduce the number of nodes involved in the query (instead of filtering later by some property), but I feel like that in this case we can achieve the same result (maybe also in performance) by considering different labels.

Answer 1

Both of your models will work fine. But to obtain the best performance, you can combine these two models into a single one. Like this:
All the Contact nodes that store emails, will have Email label as well.
All the Contact nodes that store faxes will have Fax label as well.
Relationship type between Person and Email types node will be REACHABLE_BY_EMAIL
Relationship type between Person and Fax types node will be REACHABLE_BY_FAX
Using this model, you can easily query a person's email or by these queries:
MATCH (p:Person)-[:REACHABLE_BY_EMAIL]->(email)
RETURN p, email
MATCH (p:Person)-[:REACHABLE_BY_FAX]->(fax)
RETURN p, fax
Note, that I have not specified Email or Fax labels in the query, as they are redundant.
Also, now you can query your the emails and faxes, using simply
MATCH (e:Email) RETURN e
MATCH (f:Fax) RETURN f
If the need arises.

Answer 2

You can also use
(:Person)-[:REACHABLE_BY]->(:Contact)-[:HAS_TYPE]->(:ContactType)
with 'Fax', 'Phone', 'Email' as ContactType nodes.
In your queries, using directions will help you speed up things. Your 2nd query of the second model can be written as
MATCH (p:Person {name:"Bob"})-->(c:Contact)
RETURN p.name AS Name, c.contact AS Contact
For the model I suggest, the queries would be:
MATCH (p:Person {name:"Bob"})-->(c:Contact)-->(:ContactType {name:'Email'})
RETURN p.name AS Name, c.contact​ AS Contact
and
MATCH (p:Person {name:"Bob"})-->(c:Contact)
RETURN p.name AS Name, c.contact​ AS Contact