Depends on the scope of the work you want to do, if you'll be living there at the time etc.
I personally have not but my brother and his girlfriend bought and completely redid a rowhome recently. They had the fortune of having a place to live rent free while the house was being redone, so it could be done all at once rather than piecewise.
That being said it took them over a year, a large chunk of that due to FEMA dicking around about approving their plan (work was halted for nearly four months on this one hangup). Expect permitting to be a pain. Most of that will be handled by your contractor (or it should be) but it will still be a pain and can be unpredictable.
Another thing they ran into- their neighbors tried to oppose their plan at the public approval hearing. One brought a lawyer so my brother also had to show up to court with a lawyer as well. The city wound up ruling in my brother's favor on the matter pretty quickly though. Just something to be aware of, not everyone will be against it but you could get unlucky with your neighbors.
Another hurdle, and this one comes up with nearly every major rehab project- there WILL be unexpected cost overruns. It will happen. Plan for it. Depending on the scope of the work set aside at least a few grand to cover it. If you wind up not needing it then you have a few grand to spend or invest as you please!
They went for nice, upper end but not crazy top end finishes throughout and wound up spending (in addition to the purchase price of the house) a little shy of $200,000 on redoing it. It is now a three bedroom, two full bath home with a large back patio (for their neighborhood at least), and a beautiful roof deck. They have immediate home equity in the realm of $150-200k. Their house is gorgeous and exactly as they wanted it. And they are very happy they were able to do the rehab! Depending on the neighborhood you buy in it's not only a great way to get the perfect house for you, but also a great way to build instant equity in the house.
It sounds daunting but if you have the means and the patience it could be well worth it!