Felix -
Whilst I won't even pretend to have a good knowledge of the handbuilt 1/43 genre, here's how I gauge them:
The Tecnomodel is by far the best piece I own. BBR also do a F430 GT. I sought opinion from various forums and sellers. It is the general opinion from the more experienced collectors that the models Tecnomodel produce [in particular the F430 GT and the 575 GTC] are superior to the BBR in terms of detail and finish. A camera won't pick up the interior detail on the TM F430 - which is a shame. Try and see one in a shop. So much detail crammed in such a small space. Paint is deep and perfect. Right height looks great, and the wheels are nice and large - I can't stand wheels that look too small… I think they both retail for a similar price, although the Tecnomodels seem to have a small release number, and the mounting is also nicer.
The MC12 Gasoline model I have is supposedly the 'budget' brand of BBR. Again, most investigation reveals aside from paying for the BBR name, and perhaps a nicer presentation/mounting, the Gasoline and BBR models are pretty much built to the same standard. [And I do agree that the BBR mounting is nicer, but you can buy a nice base separately, and cheaper…] Again, it's a high standard. Paint is thick and perfect. Deep gloss. Ride height is good, with a decent wheel size. Lots of small detail which, again, puts it in such a higher league compared to the more budget 1/43s that offer this particular model.
The Looksmarts don't quite have the level of detail and finish the Tecnomodel has. Not taking anything away from them though. Paint is good. Models proportions are good, with nice ride height, wheels, and interior detail. However, I picked up the LS's for around 40% to 60% of the cost of the Tecnomodel, and the difference is visible. The Scream [orange] R-GT's paint and decals look very delicate, whereas the Gasoline model I'd be happy handling off of the mount. However, I still adore my R-GTs - especially the Japan version. The model just looks spot on.
I'm looking at either a MR Collection LP640 and/or a Make Up F40 LM next.