template query -- mapped vs single

[sip]

Hello,

What would be more efficient from server point of view:

(1) Doing a mapped template for category and articles (wherever this is needed)

OR

Doing following in same template (say for example category/default.tpl)

<vte:template>
<vte:if test="{CURRENT_CATEGORY.get_id} in 'x1,x2,x5,x7,x9,x11,x51,x56,x78,x88'">

--- modified template code here different from default ---

<vte:else>

-- default template code --

</vte:else>
</vte:if>
</vte:template>

Since doing a mapped template for huge set of such categories is a maint. nightmare so this question. Same applies to the article template also. Moreover the problem with doing mapped template is also the mobile template set as that always looks for default.tpl and not sure how are mapped templates handled in mobile template set?