Effective limit on size of text type?

Using pg 7.2.1 on OsX 10.1.5

I'm trying dumping encoded email attachments into a text field. Inserts complete quickly enough that I don't notice  a
performancehit (~1 sec).  

However,

test=# \x
test=# select _incomingEnclosures from dl_event where _idNum=3010;

Takes at least a couple of minutes, either through psql or a libpq based connection.

test=# select char_length(_incomingEnclosures) from dl_event where _donorNum=804 and _responseNum=3010;
-[ RECORD 1 ]-------
char_length | 952478

Is nearly immediate.

Then again, without the \x view, I get the header of the column almost instantly, and the rest does scroll by my
console.(perhaps cached?) 

Is this an issue with the frontend or the backend?  Can I work around this by using a different data type?  (I'm not
surethat large objects are well supported in my client library) Maybe bina? 

eric