We have just got back from 2 weeks and we spent the majority of our time (especially in the later evening) at MK. We saw HEA numerous times from different positions, and while it is obviously a great technological marvel and spectacle, I personally didn't 'feel' as connected to it as Wishes. It didn't evoke the same kind of emotion, albeit good and somewhat engaging, it just seemed to be lacking and almost like they were trying to get as many 'B-side' main characters into play... but I suppose that is personal opinion.
On one of the nights I camped out for about an hour in the central island right in front of the Castle, we got a very good view. The downside is that having waited for an hour or so, all of the CM's come and and move everyone forward so you lose your vantage point! lol I understand why they do it, but it was a little frustrating. On top of that, as it is such an in demand show, I don't think they do a good enough job of marshaling people who are doing things they shouldn't and ruining the experience for others.. i.e. Standing on trash cans, being 15ft from the front and then putting 10year olds on your shoulders.... standing in front of everyone who is sitting behind you despite having an unobstructed view etc.. While these are obviously 100% subjective, it did sour the experience for me. The other nights we used HEA to go on rides without any wait! However, be warned, the second HEA finishes the FastPass lines for the major attractions will be just as long as the Standby. This we experienced multiple times on Space Mountain, TRR, MT etc... People are getting wise and booking a fast pass for the time period right after HEA and then it is a literal 'rate race' to the line! On our last night the FP line went from Space Mountain all the way to the People Mover!
A little tip for those not wanting to spend the money on a desert viewing party or putting up with a humongous crowd, if you can (and have someone willing to do it) you can get a table at Casey's Corner that will give you an excellent view of the castle, no one in front (as they prevent people from stopping on the walkway in front of the seating) and you can not only have a tasty treat, but you will get a very good experience while sitting comfortably! Obviously, this is a bit hit or miss as you cannot book tables but we lucked out one night when we were not going to stay and watch!
Here are a couple of pictures... we were 1 table back from the front.... and remember, DON'T FEED THE BIRDS lol ;o)
https://goo.gl/photos/VuMQaDmrVQoqbZyk7
https://goo.gl/photos/CHFtRyEbbnh1vVpKA
If I were to go again I wouldn't be too enamored with wanting to be 'front and center', it is a good show but for me personally (and something that is echoed by my family) I don't think it is worth all of the additional hassle to view it properly. But that is just my opinion...... I would definitely contemplate doing Casey's Corner again though! That was a right result! ;o)
Here is a Google map of the table for reference:
https://goo.gl/photos/xRVG1tCaQopgkrPVA
The view from Tomorrow Land is also not too bad, you get the music, the fireworks and a good angle of the castle projections too:
https://goo.gl/photos/BpVxjKAumeBdMi7E9
Here is what the view looks like from the SDMT side of the park:
https://goo.gl/photos/PWyE6bvUrjTiUkjS6
Here is it looking from just outside the Dumbo Ride, facing SDMTL
https://goo.gl/photos/FL7sgWomQoZDtrjh7
As final comparison, here is a screen shot of my 2.7k Video when on the center island infront of the castle:
https://goo.gl/photos/KcvLx8dYqzTXBJkC6
Here is its relevant location on Google maps:
https://goo.gl/photos/SR1VLbjVpTMgSxNX7
And both together for ease of viewing:
https://goo.gl/photos/tWuu8iHG7EfFs2yDA