I group of 35 of us just went down to Darien Lake last weekend. About 10 people purchased the Roam mobility SIM cards prior to departing including myself. My DW, who is on Wind, I just upgraded to the $15 Unlimited US Roaming add-on.
A few people had initial hiccups getting the Roam to work but primarily it was caused by those individuals not reading all the instructions provided by Roam. We had created a Whatsapp group for everyone prior to departing and used it the entire length of the trip. Roam worked perfectly for our situation. We were all able to communicate quickly and easily, while doing are cross boarder shopping on the Friday. While at the park people could share pictures of their location or of the activities they were doing, so everyone was aware of what was happening throughout the park.
From a speed perspective, I found my DW's Wind phone was a little better service wise, especially comparing the upload time of photos her's uploaded twice as fast as myself on Roam. However, neither were what I would consider "slow".
We found Staples had the best price for the Roam cards at $14.95 each + taxes. Setup was a breeze and I like that you can pre-book the time you want to start the 1-day, 3-day, 7-day plans. Also, most of us received a credit of $3.95 as well because we all setup our Roam SIM cards in September when they had a deal on. I used the credit, paid the $1 LTE upgrade fee and for $11.50 received unlimited calling, text and 900MB of data for 3 days.