I would definitely go with the TCII without hesitation. While the Patriot is a fine unit, it is a Prosumer unit where the TCII is a full commercial grade unit built to a higher spec that will give you better reliability over the years. You also move up to the Velocity deck which is arguably the best deck available on any machine. I t cuts extremely well in wet conditions as well, so if you get caught out in the rain, or in heavy morning dew or wet conditions you will have far better results over the Hero deck. The Patriot is limited to a maximum engine size of 27hp, whereas the Tiger Cat can be spec'd with a 36hp which would be a monster with the 61" deck and simply nuclear with the 52" deck...

You also pick up a couple mph so it could likely shorten mowing time a bit...time is money. 😉
At any rate, depending on specs you're looking at a $2,000 to $4,000 difference and it would be money very well spent IMHO.
For that size property, I would consider the 36hp Vanguard with the 61" deck as it's only a $600 upcharge over the very fine and capable 26hp Kawasaki, but you mention cutting field grass and the difference here will pay HUGE dividends with the 36hp engine and without a doubt offer the best bang for the buck!!
Are you a veteran?? If so, you should receive a bit of a discount as well.