There are a couple of full size fields in the Houston area. Three are in schools. One is in a government facility. The biggest benefit is that teams can scrimmage before and during the competition season. 118 used to invite teams going to St Louis to scrimmage at their field when theirs was the only one in the area.
There is a STEM center in the west of Houston with enough shops for 8 teams, a full-sized field, a shared machine shop and meeting rooms. Currently 5 FRC teams and some VEX teams are based there. One of the local Kickoff events has been held there in recent years and I believe some scrimmages. It has also been used for FLL Practice Day events and other non-robotics STEM events.
The value will depend on your situation. One opened in the north of Houston a couple of years ago and now has 2 teams that are from the same school based there. The other schools in the district were too far away and so no plans were made to base any other teams there. They have hosted some pre-season scrimmages there.
Hopefully someone from the Toronto area can give their input since they have several full-sized fields that have been made available to the local teams.