It's entirely subjective but on the whole, yes, they do look amazing in person.
There's always going to be a Hot Toys vs Sideshow debate. I don't really want to weigh in on that because they both have their own merits and now seemingly their own niches. Both will remain relevant in some way. Hot Toys typically wins out in portrait work, but I think Sideshow has the potential to keep making great troopers and armored or non-human characters. Hot Toys isn't perfect. Sometimes their sculpts can be off, and there've been some poor choices in materials for a number of figures. But they are otherwise hard to beat in the 1:6 world offering amazing and consistent paint work, intricate details, and crafty engineering. I will say Hot Toys figures tend to look very close to their pre-production prototypes with the exception of a few incidences. Sideshow can be a hit or miss.
Admittedly, some collectors can get jaded over time and nitpick every single perceived flaw in a figure and end up unhappy, whether the flaw is real or not. (ie. the helmet is a little off, the fabric isn't the right blue). Don't get me wrong - I can be a little overly critical sometimes and major inaccuracies can definitely be a legitimate dealbreaker. At this price point, you should expect better than average.
But typically when taken as a whole, many figures from Hot Toys and Sideshow tend to be overall very awesome.
If you think it'll make you happy, order it. If you get it and it's amazing to you, keep it. If not, pass on it or sell it. Most of these figures, you can usually get your money back, get away with a small hit, or even make a profit if you're so inclined. Whereas whenever you typically buy other types of collectibles, you're generally not getting anything back,
For me personally, my first high end 1:6 figures were the Hot Toys Iron Man Mk VI and Sideshow's Sandtroopers. I used to collect all sorts of other toys but seeing Iron Man so well done in such an imposing scale really blew me away.