Array of structures - two ways to approach - which is better?

Folks - I've been trying to create an array of structures, but I bumped into problem that lead me to an example that is completely different. I'm trying to figure out which is valid. In general, it comes down to this:

(1) myStructure .firstName
vs
(2) myStructure.firstName

The problem with the first is that I can't find a way to discover the size of the array, which leads me to suspect this is not a valid method. The problem with the second is that you must redefine the structure for EACH array element, which seems like it would add a lot of overhead.

Any advice? Sample code attached.

Thanks!

************* Sample (1) **************
<CFSET sCust=StructNew()>
<CFSET vCustCount = #rsMailAuth.recordcount#>
<CFSET i = 0>

<CFOUTPUT QUERY="rsMailAuth">
<CFSET i = i+1>
<CFSET sCust.userId = #rsMailAuth.userId#>
<CFSET sCust.validEmailSource = #rsMailAuth.validTcEmails#>
<CFSET sCust.authKeyword = #rsMailAuth.tcEmailKeyword#>
<CFSET sCust.authKeywordLoc = #rsMailAuth.tcEmailKeywordLoc#>
</CFOUTPUT>


************* Sample (2) **************
<cfset strTest = arrayNew(1) >
<cfset strTest[1] = structNew() >
<CFLOOP INDEX = "i" FROM="1" TO="5" >
<cfset strTest = structNew() >
<cfset strTest.id = i>
<cfset strTest .name = "#i#name@mail.com">
</CFLOOP>

<cfoutput>#arrayLen(strTest)#</cfoutput>