I think you cannot make a blanket statement about this. Remember that implementation of the chips ( components , board layout, power supply etc. )affects the end result. So you will actually be comparing a 'system using the TDA2050' against a 'system using a LM3886 chip'.
I've done this before. My TDA implementation sounds very good . The LM3886 has very obviously ( audibly) more power than the 2050. I felt the 2050 system had more bass control than the 3886 . Treble was also a bit brighter in the 2050 (?) . Could be because of more hf distortion content. The 3886 measured better of course.
If you need more power you certainly need the 3886. If not , you can very easily stay with the 2050 and enjoy the sound and save the time to be spent on building another amp and use it to listen to more music. And buy more music ?
some years ago I built LM3875 and TDA7294 kits, both fairly cheap. The sound quality of the TDA7294 was considerably better. The LM3875 was so far behind that I could not be bothered to build the second kit and try to tweak it.
you can call it what you want, as long as you don't advertise it as such.
Gainclone is a very specific topology.
I don't like the philosophy that the Gainclone topology adopts. There are many better circuits, some much better at avoiding the reliability pitfalls of the Gainclone.
A clone is an exact copy of 'something'.
Originally the Gainclone was a copy of the Gaincard by 47 Laboratories of Japan. It used a LM3875 chip and was a minimalist design with no conventional PCB . It did have a small pcb but it is not used like it generally is.
Today many people appear to call any amp a Gainclone if it uses a single chip power amp like the LM 38xx series or their equivalents from the TDA arena.
The bottom line is that each design is just another implementation of a chip power amp and is in no way a copy of the original design which was called a Gaincard. In fact most 'copies' were heavily modified and cannot really be called 'clones'.
So there you are , like AndrewT said ... call it what you want .....it will be just another chip power amp and could possibly be better than the original Gaincard .
If you want to read up on the original Gaincard / Gainclone , here are some links :
I have done them both. LM3886 sounds way better, as long as you do not approach the clipping area. The sound is very clear, especially for midrange and high frequencies. Try them both and choose the one you like. TDA7294 is also good, but it seems to sound softer, at leat for my ears.