I bought a used intuos3 a couple month ago. After a bit of use the pen nib drops now slightly when I put it to the tablet. I can really feel it moving if I put my finger on the eraser, another on the nib and push it back and forth. I tried opening it but couldn't take it apart even when using force. I taped the top as a temporary solution.
I'm thinking about upgrading to an intuos4 M since it only costs 179 euros (~230 usd) now. I also looked at the intuos5 M touch, but a lot of people seem to have issues with the touch feature and apparently it's not as useful as it seems. Also at a 320 euro price tag, it's would be a really huge investment. The intuos5 without touch is much cheaper (260 euro), but doesn't seem to have any advantage over the cheaper intuos 4.
The intuos4 seems like a good deal, but I'd just like to know if any artists have found the touch features of the intous 5 useful?
you should be able to disassemble the intuos grip pen yourself
the key is to do it in slow, pulling away motions, while slightly tilting pen parts up and down (*slightly*)
make sure your hands are really clean and dry and you have plenty of space around
also do it on a table, because there're a few small strings inside that aren't soldered (esp. eraser side one) and you risk them getting lost.
probably hold it with eraser side down as an extra safety measure.
btw you still should be able to purchase a replacement intuos 3 pen from wacom store, it would be cheaper.
as far as intuos 5 goes, I got myself a M sized no-touch after using L sized intuos 3 and quite happy with it.
it's basically identical to intuos 4 except for a new design and an optional wireless module.
also, intuos 5 has only one usb port, while 4 has two on both sides of tablet.
if you're on mac, I'd strongly recommend getting an apple touchpad; if you're on windows, touch features are nice, especially photoshop canvas panning
(can't comment on painter yet, but 12.2 got wacom touch functions working well too apparently.)
IMO the touch feature is pointless for my workflow.
I use Win7.
I had a medium Intuos4 and got a small Intuos5 for travel, however I preferred the feel of the Intuos5.
Both are great! I sold my intuos4 and use my intuos5 now, LOVE the wireless feature, means I can lounge around and draw on the TV and stuff... I've customised all the buttons for my workflow, so yeah, it does swell.
If you're a Mac user and use multi-touch a lot in your workflow, get the Intuos5. if not, get the Intuos4... But if wireless sounds good to you, get the Intuos5.... ah confusing.
I miss the LED display on the Intuos4 though, but besides that, I prefer the intuos5.
Keep in mind that with touch models you can't replace the surface sheet (which you need to do in case you damage/scratch it or need - you will need - to wipe out the "paper-like" finish).
Sending a tablet back to Wacom (as if it got damaged) would be quite expensive. Plus, you would remain without a tablet for a more or less prolonged period of time.
If you have to really get an Intuos5 tablet I would suggest the Medium, pen-only version (no touch) with has got a user-replaceable surface sheet.