I have a NH TC35A (Shibaura) Boomer that has been a really good tractor. I have been thinking about getting a 45-50 HP tractor to have a little additional 3 PH and FEL lift capacity. I first looked at the Boomer 50, Kubota and a Kioti. They are all nice tractors including the Boomer 50. Comments from the owners in the LS section made me want to look at a LS. It is definitely worth looking at. The R4041 and R4047 (same frame with different HP) seem to be very well made tractors. I was traveling near Rocky Mount, NC where the LS tractors are assembled. I stopped and tested one at a local dealership. The R4041 (Shuttle) is very smooth and the controls are well laid out. The FEL works great and will lift a pretty heavy load. The R4041 was quoted for ~$20,000 with the FEL and filled tires. The R4047 was ~$21,000 for the same set-up. They are the same tractor, but the R4047 has 6 more HP. Same lift capacity from the FEL and the 3PH.
The frame does not seem as big as my TC35A. I like the seating position of my tractor because you can see the top of the bucket from the drivers seat. You set lower on the LS and have to view the bucket from the side like most other tractors.
It would be hard to trade my TC35A because it is like part of the family and it is totally paid off with 481 hours on the meter. If I were looking at tractors again I would definitely consider a LS R4041 or R4047. It is just about the rights size frame for brush cutting and working around trees. They have strong FELs and nice features (QA Bucket, 2 rear remotes, deluxe 3PH, electric PTO) that are standard.
So to answer you question about the "New" Boomer tractors .... I would definitely own one, but I would buy the LS version and pay about $5K less for it vs. a NH Boomer.