Is it worth buying park to park tickets just to see both HPW?

[Bairstow]

And apparently skipping every show and non-ride experience?

Yep. Other than that little magic show sales pitch they do at Lost Continent and spending some time at Camp Jurassic.
We slowed down the pace a lot on the second day and tried to enjoy every nook and cranny of Diagon/Nocturne Alley.
Again, I'm not sure a first-time visitor to Universal could pull off that sort of day, or would even want to, but if @disney_exotic101 isn't doing the coasters or water rides it does free up a lot of time.

 

[disney_exotic101]

We visited Universal on our last trip a couple weeks ago and both parks were pretty dead. Several wait times were drastically incorrect, for example Gringrotts supposedly had a 25 minute wait and it was a walk on every time we rode it, so I wouldn't buy any kind of express pass unless I knew for sure the parks were legitimately busy.

As for getting tickets for both parks, if the parks are not busy you can pretty much get through both of the high points for each park pretty fast with a lot of time to spare to check out the lesser attractions or repeat your favorites.

I will be visiting near the 2nd week of december but I'm not sure it will be busy. I hope there wont be much of a long wait in the lines. Thank you for you feedback.

 

[disney_exotic101]

In mid October, in one day, we were able to do:

Escape from Gringotts (wait was ~80 minutes due to breakdowns)
Mummy (twice)
Men in Black
Hogwarts Express
******PARK CHANGE*****
Fire Dragon
Ice Dragon
Forbidden Journey
The Cat in the Hat
Hulk
Doctor Doom's FearFall
Spiderman
Jurassic Park
Camp Jurassic
Ripsaw Falls
Bluto's Bilge Rat Barges
****PARK CHANGE****
Simpsons Ride
Transformers

Now keep in mind this was using Express Pass, early park entry, and going at full park-commando pace all day until park closing.
We also had a second day to mop up anything we didn't get done on the first one.

Very extensive plan you listed!!! Thanks! What time did you arrive at the park and what time did you leave in order to experience all the attractions you listed?

 

[disney_exotic101]

Yep. Other than that little magic show sales pitch they do at Lost Continent and spending some time at Camp Jurassic.
We slowed down the pace a lot on the second day and tried to enjoy every nook and cranny of Diagon/Nocturne Alley.
Again, I'm not sure a first-time visitor to Universal could pull off that sort of day, or would even want to, but if @disney_exotic101 isn't doing the coasters or water rides it does free up a lot of time.

Since I am a first timer and I plan to skip all rollarcoaster rides and water rides. Do you think I be able to experience all the attractions in both parks? What time should I arrive to make the most of the day?

 

[Donald Razorduck]

Depending on how long it takes us to do Animal Kingdom and Hollywood Studios we may try the two parks in one day bit because I know my 12 and 11 will demand it when they see it. Going to be there Feb 8th thru 13th. Will hit the Universal parkss in mid week and all crowd calendars say those dates are close to slowest of the year.

If not, we are planning a cruise on Disney for 2016 and will add two days for Universal.