Eureka was an awesome show at the beginning, but it took a turn for the worse when they started ignoring their own world-building. Remember in the first season it was established that Eureka was a top-secret government project and its entrance was hidden from the world so that strangers couldn't pop in unannounced?
Fast forward a few seasons and you start seeing story-lines centered around strangers popping into town unannounced. 
Even without the contract dispute I really don't see it having lasted much longer. The writers were running out of ideas and didn't know what to do with the characters.
Warehouse 13 was a very enjoyable show. The quality between episodes wasn't always high, but it was nearly always entertaining. It ended right where it needed to. The characters had run their course, but I see a lot of untapped potential with the premise of the show. Maybe in a couple years there will be a Warehouse 14 with an entirely new cast.
-Innuendo
I thought in Warehouse 13 It wasn't so much the characters running their course, as after the brilliant 2nd Season they got stuck trying to follow the double act of Egyptian-Awesome and Helena Wells stealing the show! So season 3 was a little tricky. But then when one writer hands you a broken script the others have to now deal with it. So once the Astrolabe entered the picture, with the power to *reset the entire world*, "only" at the cost that it just makes the user crazy, they created an Elephant in the Room. So the whole Dark Artie season 4 faltered.
C. C. H. Pounder / Mrs. Frederic mastered her "one-act" of stern glares, but I'm betting the actress began to grow tired of the role because she tended to have useful tips, but didn't "do much" to "save the warehouse". And then the last season had too few episodes for what I thought was a really promising premise.
If I recall the show correctly, Paracelsus was among the smartest of all the caretakers. To me, he showed the true danger of the warehouse: each artifact is nasty all by itself. But when you start playing Magic, the Artifacts Gathering and smashing them together, TRULY astounding things are possible!
Some can be really good, if used responsibly. All of Season 4 was about Artie's desperate attempt to undo the total warehouse destruction.
I'm borrowing a bit of chess concepts here. Let's call Artie a "Master" of the warehouse. He's pretty good. But his solution was the Astrolabe that only worked for 24 hours, and left him insane.
Paracelsus smashed three artifacts together, and created a *full time machine* with *apparently no downsides*.
So that should have scared the beejees out of Mrs. Frederic, because Paracelsus was a "Grandmaster" who just happened to be a psycho.
Plus, using the mid season break, the Season 5 opener had some of the best set design ever in the show.
