I'm a Chicago native, so some here might assume that I may be a bit biased in my review, considering Portillo's is a legendary Chicago institution. However, that's definitely not the case. If anything, I might be a little tougher when reviewing a Chicago icon that's trying to be as successful in other cities and states as they are in their home one.
That being said, I have visited more than once these Houston area Portillo's locations: Katy, Richmond, and Willowbrook, with the Katy and Willowbrook ones the most often because of their proximity to where I work and live, respectively. I have both dined in and used the drive-through in both locations.
The biggest test for me was, quite simply, the taste of the food. In other words: did their food taste as good as it does in Chicago? Quite honestly, a definite yes! While I haven't had all the items on their menu, the food I HAVE eaten has been terrific. I'm somewhat of a boring traditionalist when it comes to Portillo's. I usually go for their hotdogs and Italian Beef sandwiches as well as their Polish sausage and Italian sausage (both alone and as part of a combo sandwich, like Italian Beef w/ Italian or Polish sausage). Where beverages are concerned, I will occasionally grab me a chocolate cake shake. All of these items are delectable treats.
Their hotdogs are true to form: Vienna Beef franks that are absolutely delicious! Their Italian Beef is tender and delicious. The chocolate cake shakes are just as they are in Chicago: sinfully decadent and waist-expandingly delicious.
The most frequent complaints I read and hear from native Chicagoans about the Portillo's restaurants here in the Houston area——there is also one in Tomball, Humble, Stafford, and more to come——is that they don't have a certain item on their menu. The #1 most complained about missing menu item is the famous Portillo's tamale. There are even many native Chicagoans who are so upset about this that they refuse to patronize Portillo's until the tamale is added to the menu. Now, if this was the absolutely ONLY thing you eat at Portillo's, then I can understand your not going there until they have tamales, but if you're going to boycott Portillo's completely and definitively, not even buying a Coke or a hotdog from there, you're just being a petulant child.
Note that in my review here, I'm not focusing on the different options for their menu items. It's really irrelevant and stupid to review how Portillo's serves their Italian Beef sandwiches if, for example, someone prefers them with their gravy on the side while another prefers the gravy poured onto the beef. I prefer to instead focus on the quality of the beef, gravy, and bread. All 3 of these have been consistent winners at the Houston Portillo's I have visited. I personally prefer my Italian Beef sandwiches to be "wet," which means after the sandwich is created, the entire thing is submerged into the gravy, thereby making the entire thing a wet wonder. It's absolutely delicious, but you have to eat it sooner than later, lest it completely fall apart on you. They use the French Gonella bread, which is virtually impossible to find in grocery stores in the Houston area. This type of bread is the ONLY type that should ever be used to make a real Italian Beef sandwich. I commend Portillo's for staying true to its roots in this regard. The beef and gravy (or sauce or juice——whatever one wishes to call it) are both just like they are in Chitown, that being heavenly tasty.
Their hotdog, which is probably one of their most famous menu items, is wonderful. I briefly alluded to it above, but I wish to mention one specific part of their hotdog about which I was very curious and concerned when I first heard a couple years ago that Portillo's would be coming to southeast Texas——the poppyseed bun. Poppyseed buns in Texas are as common as are palm trees in the arctic. Seriously. You cannot find poppyseed buns anywhere. I should know. I've tried all the grocery stores, bakeries, and numerous other joints. They somehow do not exist.