sp_xml_preparedocument VS nodes()

I am considering converting a stored proc which uses sp_xml_preparedocument to a select using the node() syntax. I made two sql scripts, one of each method with identical input xml and ran a query plan on each of them. To my surprise, the Sp_xml_preparedocument seemed to produce the better query plan. The Estimated subtree cost for sp_xml... was 3.36433 for 10000 rows and the estimated subtree cost for nodes() was 421.126 for 60 rows. Am I missing something or is sp_xml_preparedocument still the best method to shred an xml document?

sp_xml code:

DECLARE

@idocINT,

@trans_idint,

@after_docxml,

@record_typeint,

@sm_session_idnvarchar(50),

@trigger_start_timedatetime,

@user_idint,

@fot_serial_idvarchar(50),

@system_idint,

@uudata_delimitervarchar(2),

@retcint

SELECT @after_doc='<ROOT><transaction fot_flag="" fot_serial_id="91bec7f9-edd7-4abb-b912-cef35f753e6b" record_type="1" user_id="6" sm_session_id="a31000ef-fa7f-41c8-8de2-2572c471ed6d" uudata_delimiter="#;" system_id="1"><voice_transaction alias_id="4" trans_size="16453" machine_id="7" comp_code="0" tran_start="2006-04-26T09:11:27" tran_stop="2006-04-26T09:11:44" line_id="1" ext_id="6409" tr_filename="extT8.1_04_26_2006_09;11;27.wav" tr_path="\\IRTXQFNTI001\Recordings\0001" /><screen_transaction alias_id="" trans_size="" comp_code="" tran_start="" tran_stop="" screen_delay="" ip_address="" tr_filename="" tr_path="" /><tx_trigger_info /><tx_classification_info /><cti_transaction_info><cti_transaction userdata="2#;QRecorded= #;QFOTSerialID= #;" eventtime="2006-04-26T09:11:27" party="0" serialid="db606227-44a8-4af2-97a9-e0261b8d256c" ani="7703808051" dnis="6241" event="20101" appearance="0" infoonly="0" number="6409" cause="0" /><cti_transaction userdata="2#;QRecorded= #;QFOTSerialID= #;" eventtime="2006-04-26T09:11:44" party="0" serialid="db606227-44a8-4af2-97a9-e0261b8d256c" ani="7703808051" dnis="6241" event="20103" appearance="0" infoonly="0" number="6409" cause="0" /></cti_transaction_info><tx_sys_classification_info><sys_classification plan_id="10" plan_session_id="0" plan_assoc_id="0" class_id="-8" requestor_id="0" trigger_start_time="2006-04-26T09:11:27" user_id="" trigger_stop_time="2006-04-26T09:11:44" /></tx_sys_classification_info><tx_warning_info /></transaction></ROOT>'

select @after_doc

EXEC @retc= dbo.sp_xml_preparedocument @idocOUTPUT, @after_doc

SELECT @record_type= record_type, @sm_session_id= sm_session_id, @user_id=CASEWHENuser_id<= 0THEN-1ELSEuser_idEND, @system_id= system_id,

@fot_serial_id= fot_serial_id, @uudata_delimiter= uudata_delimiter

FROMOPENXML(@idoc,'/ROOT/transaction',1)

WITH(record_typeint,

sm_session_idnvarchar(50),

user_idint,

fot_serial_idvarchar(50),

fot_flagtinyint,

system_idint,

uudata_delimitervarchar(2))

SELECT @record_type, @sm_session_id, @user_id, @system_id,

@fot_serial_id, @uudata_delimiter

node() code:

DECLARE

@idocINT,

@trans_idint,

@after_docxml,

@record_typeint,

@sm_session_idnvarchar(50),

@trigger_start_timedatetime,

@user_idint,

@fot_serial_idvarchar(50),

@system_idint,

@uudata_delimitervarchar(2),

@retcint

SELECT @after_doc='<ROOT><transaction fot_flag="" fot_serial_id="91bec7f9-edd7-4abb-b912-cef35f753e6b" record_type="1" user_id="6" sm_session_id="a31000ef-fa7f-41c8-8de2-2572c471ed6d" uudata_delimiter="#;" system_id="1"><voice_transaction alias_id="4" trans_size="16453" machine_id="7" comp_code="0" tran_start="2006-04-26T09:11:27" tran_stop="2006-04-26T09:11:44" line_id="1" ext_id="6409" tr_filename="extT8.1_04_26_2006_09;11;27.wav" tr_path="\\IRTXQFNTI001\Recordings\0001" /><screen_transaction alias_id="" trans_size="" comp_code="" tran_start="" tran_stop="" screen_delay="" ip_address="" tr_filename="" tr_path="" /><tx_trigger_info /><tx_classification_info /><cti_transaction_info><cti_transaction userdata="2#;QRecorded= #;QFOTSerialID= #;" eventtime="2006-04-26T09:11:27" party="0" serialid="db606227-44a8-4af2-97a9-e0261b8d256c" ani="7703808051" dnis="6241" event="20101" appearance="0" infoonly="0" number="6409" cause="0" /><cti_transaction userdata="2#;QRecorded= #;QFOTSerialID= #;" eventtime="2006-04-26T09:11:44" party="0" serialid="db606227-44a8-4af2-97a9-e0261b8d256c" ani="7703808051" dnis="6241" event="20103" appearance="0" infoonly="0" number="6409" cause="0" /></cti_transaction_info><tx_sys_classification_info><sys_classification plan_id="10" plan_session_id="0" plan_assoc_id="0" class_id="-8" requestor_id="0" trigger_start_time="2006-04-26T09:11:27" user_id="" trigger_stop_time="2006-04-26T09:11:44" /></tx_sys_classification_info><tx_warning_info /></transaction></ROOT>'

select @after_doc

SELECT @record_type= trn.value('@record_type','[int]'),

@sm_session_id= trn.value('@sm_session_id','nvarchar(50)'),

@user_id=CASEWHEN trn.value('@user_id','int')<= 0THEN-1ELSE trn.value('@user_id','int')END,

@system_id= trn.value('@system_id','int'),

@fot_serial_id= trn.value('@fot_serial_id','varchar(50)'),

@uudata_delimiter= trn.value('@uudata_delimiter','varchar(2)')

from @after_doc.nodes('/ROOT/transaction')

AS node(trn)

SELECT @record_type, @sm_session_id, @user_id, @system_id,

@fot_serial_id, @uudata_delimiter

[16346 byte] By [rbennet8] at [2007-12-27]