I have a TX Sport Cub with the Jabiru engine. When flying solo the plane is a bit nose heavy, but still well within the allowable CG envelope. That said, I cannot completely trim out all the nose down pressure on the stick when I slow down to landing speed.
The use of brakes should be approached with caution when flying solo, because you can definitely put it over on its nose if you get carried away. People have done that, but not me. However, this is typical of the Cub clones out there that use any of the heavier engines (other than Rotax).
The main thing the Jabiru has to recommend it is that it is lighter than either of the Continental engines -- about 30 pounds lighter than the O-200-A and 15 or so pounds lighter than the O-200-D. The Jabiru is a bit more work to sort out initially, and as Legend/Texas Sport does fewer of these engines, they are better at dealing with the Continentals.
When I built my plane the O-200-D engine was not available, so I was looking at saving 30 pounds by going with the Jabiru. Given my weight and that of the friend who would most likely fly with me, that 30 pound weight saving was too much to pass up. The O-200-D engine cuts that weight saving in half, but the Jabiru is still noticeably lighter. The Jabiru has caused me more frustration to get it sorted out than I expected, but it runs fine now. If I had it to do over again I would probably still go with the Jabiru, because the weight saving is that important to me, and I believe that the Jabiru is a good engine despite its quirks.