I've done it the past two years, and it is a pretty good ride. I did the 62-mile distance both years, so can't comment on the 100-mile course (which they added for last year).
Some, but not all...I remember the Bluebonnet Express as being hillier than TdP, but it's been a while since both so I'm a bit hazy on the details. I want to say that the BBX went farther west, while the TdP route went more southeast? I could be totally wrong, though, since I'm terrible with cardinal directions. (And thus no help at all. ) Anyway, here are my comments from last year's ride report, which may give you some idea:I'm guessing that it probably uses the same routes as the Bluebonnet Express.
"As for this ride itself, it wasn't bad. The course was nice, good pavement, no terrible back roads like on the KFC route. The SAG support was out en force, to the point where I was pretty sure one of the trucks was tracking me specifically. The rest stops were well staffed and stocked, and the one with wet bandannas was there again this year, which I appreciated immensely.
A couple small complaints--the start was a little shaky. They meant well, starting the 100/81-milers 15 minutes ahead of the 63s, who were 15 minutes ahead of the 47s, and so on. However, it was too much time. There was a lot of impatience, and it didn't seem like any of the shorter-route cyclists knew precisely when they were supposed to go. I ended up going with the 3rd wave of 100 milers, because at my speed? The earlier I start, the better. As it was, I got on the road around 8:00.
Also, the festival closed down a little early for a charity ride with a 100-mile course. When I got in at 1:30ish, the musical acts were done, they had already shut down the food tent, and everyone was getting ready to raffle off the big prize. By 1:45, the raffles were over and they were giving away cases of drinks and packing things up. Even for 100-milers that left right with the first wave at 7:40, this seemed excessively early to me. I guess if you couldn't ride a century at a 17 mph pace (and that's with no stops), you were out of luck on the ride festival on this one. I had expected to hang out until at least 3:00 for the bike raffle. If I had chosen the 100-mile route, I would have been upset...particularly if I had bought any additional raffle tickets, since it was a "must be present to win" sort of thing.
But other than those minor things(which were probably because they just added the longer routes this year), it was a good ride for a good cause."
So, for what it's worth. Hope that helps, at least a little!