I'd definitely recommend getting a used one in your spec, or at least similar if you're not afraid of doing a bit of your own customising (remember, you can always remove/move the weights in the pallets).
In terms of comparisons, the only think I can really comment on is in terms of launch angle.... the 16x19 launch angle is ridiculous, I feel it has an even higher launch than when I used to play with my GrapheneXT Extreme Pro's.
The 18x20 is completely the opposite, super low launch angle which catches me off guard quite often (i haven't played enough with it to get used to it yet).
Another point of reference would be to my Head 360 Radical Pro's 16x19, but I find the Gravity Tour 18x20 and 360+ Prestige Pro 16x19 to all fall around the same ballpark in terms of launch angle (at least, I can go between all of them without having to adjust too much), the Angell 18x20 is lower, and the 16x19 higher.
One thing I would consider is how much of a string breaker you are, the Angell 16x19 seems to absolutely chew through strings. I'm not a big string breaker by any means, it takes me about a month of hitting 3 times a week for ~2 hours to go through a poly/multi hybrid on my Radical Pros (so ~24 hours), on the Angell 16x19, i did it 2 weeks.
I'm planning on trying some much thicker gauges in the Angell to see if it can alleviate the string breakage and might even lower the launch angle a bit.