Check for changes in a text column
Can you implement an INSTEAD OF UPDATE trigger? - a quick test on my local instances indicates you can reference the inserted and deleted tables.  Naturally, you still have to apply the real update.

here was my quick test

create table TextDataTypeTest (Col1 text)
insert into dbo.textdatatypetest (col1) values('test')
----------------
create TRIGGER dbo.TextDataTypeTest_Trigger
   ON  dbo.TextDataTypeTest 
   instead of UPDATE
AS 
BEGIN

select col1 into #Before from deleted
select col1 into #After from inserted

select * from #Before

select * from #After
update a 
set a.col1=b.col1 
from dbo.textdatatypetest a join
inserted b on 1=1

END
GO


update dbo.textdatatypetest set col1='oneforalx'