Vintage Dual 1228 Turntable : worth to upgrade cartridge ?

Norman, 
the link on Linn LP12 given by you makes really some hard but very interesting reading for new anolog enthusiast like me . Also it is kind of eye opener demanding more neutral and realistic self assessment, of any audio gear for that matter , in future rather than be simply or solely driven by so called reviews . I did not know of this guy Arthur Salvatore , but he sure has lot to offer to audio community . 
Thanks for bringing up this here. 

 One other thing I did with my Dual and P+E was to clean all the headshell leads with aa toothpick and the tonearm contacts up in the arm first with Deoxit red and again the second time with Deoxit Gold contact conditioner.I used a toothpick to clean the clip leads that go into the cartridge and treat with Gold.I even took the stylus out of one of my cartridges and did the tube that goes into the body.I heard a difference as well as my entire system which I tuneup every few months with the Gold.

playpen,
 I have just done very similar cleaning only last night on my Dual . I took out the headshell , disconnected the 4 delicate wire leads from cartridge pins , Deoxit with N5 type first then with 100 % solution to clean all 4 pins of cart, and the 4 brass clips of lead wires ( I used thin paint brush to apply it within the tiny holes), left them overnight for chemical actions of corrosion removal. Now  since you mentioned , I will even clean with toothpick . It is kind a difficult to clean the inside surface  of  "clips" which is the real contact area.  Then apply Deoxit Gold with brush. I did not thought of cleaning the " stylus tube", but will sure clean it tonight before reassembling it tomorrow. 

The Linn is a decent turntable, but that is about as far as it goes.  If one listens using a blind A/B, you'll never choose the Linn over a good idler or direct drive table.  There are so many 'reviewers' who used to use Linn as a reference.  Art Dudley for example.  I was so excited when I bought my Linn, then when it was home and set up it was disappointing. My dealer told me to 'let it brake in', months went by, then a year.  Then a cartridge upgrade, tonearm upgrade, bearing upgrade, motor upgrade, power supply upgrade, cables upgrade, plinth upgrade, it was never ending. Within three years time we had literally rebuilt the Linn.   I had a Dual 1219 prior to the Linn, with cheap crummy cables, and it sounded better in soundstage, bass, definition, etc.  It was just a more 'solid' presentation.  To me… and that's what mattered.  I bought the 1229, rebuilt it, replaced the tonearm and am very happy.  I then rebuilt a Garrard 301 and mounted a SME 3009 and it too is wonderful.

I have less than half the cost in the Dual, tonearm, Garrard and tonearm then I had in the Linn and that was with a custom plinth for the Garrrard. I am now going to be tackling a EMT, but that is going to take quite a bit as it's kinda rough and parts are expensive.  I will do some of the work, then have a local shop finish it for me.  It has to be perfect.

Enjoy your Dual, when you can, and only if you feel the need too,  upgrade.  But make sure the upgrade is an actual upgrade in sound, not just in cost.

Playpen, sounds like you've found some good tweaks to make the PE even better!  =)

Norman

Norman,
" Enjoy your Dual, when you can, and only if you feel the need too,  upgrade.  But make sure the upgrade is an actual upgrade in sound, not just in cost."

Yes, I am really enjoying my Dual as of now and find it more and more musical and wish to spend more time listening to it. As it happened , my CD Transport has gone for some repairs for last 3 weeks and that forced me to use Dual TT for consistently longer period. Now looks like I have started to discover the beauty of analog sound. 
My new JICO stylus will be arriving before end of this month and may add to the pleasure of listening. 
Looks  like I am fine with this Dual for the time being . Future upgrade , after a year may be , will surely be, like you wisely advised , " on merit of sound , and not just cost". 
I have one question : despite cleaning of cartridge , stylus , etc, my Dual still makes "thud"  noise ( through speakers )  when the tonearm lifts at the start  and again when stylus sits on the leading groove of the record . During the play of entire record , there is absolutely no issues. "thud" nose is unpleasant (and scary at higher  volume level !) . What could be the problem and how to solve it ? suggestions will be welcome.
Thanks