According to your doubts about convertible laptops I don't recommend them much because they tend to be very expensive and offer basic hardware
When it comes to price to performance nothing under 14 inches is ideal, indeed 14 inches is perfect for mobility
But if your needs involve getting your device into a very small place the only option is a convertible or ultrabook
It also depends on the software you require. When it comes to gaming don't expect something with 11 inches, and 15.6 is the most common size followed by 17.3 inches (which is too much for my taste)
For editing it reminds us the same thing. 13.3 inches and above
But if you only perform pretty normal taks, web browsing, light multitasking, multimedia (not gaming) etc you'll be picking a basic laptop (dual core, 4GB of RAM) with an SSD
Regarding brands based on what people and reviws say here is my conclusion:
ACER: Cheap but not even close to the best: improveable screens, cheap design, get hot easily, bad service
HP: Similar to acer, at times they are not even cheap and its performance decreases thanks to throttling, even worse designs than acer, poor quality and sopport
LENOVO: A bit better, good looking designs, good keyboards, good construction, good performance ad a drawback needless software and overpriced at times
MSI: Most of MSI laptops are either gaming or workstation laptops so they are recommended for those purposes. Great keyboard and touchpads, competitive prices, always innovating with smaller or more powerful solutions. Unfortunelly they don't look very good from my point of view
DELL: One of the best laptop brands since long ago, pretty cool esthetic, they run quite cool, gorgeous screens and in case of alienware they are always innovating. Drawbacks: Alienware laptops are overpriced
ASUS: One of the best brands too, really impressive designs, great quality, exceptional looks, excellent keyboards and touchpads, good screens, run cool and quite. Drawbacks, at times they are expensive
TOSHIBA: I haven't seen many toshiba laptops lately, as a matter of fact they get more expensive and you don't find good components on them but their screens and build quality are close to the best
APPLE: Stunning design, wonderful screens, very small, powerful for editing and any sort of content creation application. Friendly OS, build quiality. Disadvantages: really pricey, there are literally no cheap apple laptops and getting one of these because of the friendly interface is difficult
Nevertheless this depends on the model in particular all brands have both good and bad laptops so you'd better checked how a model in particular is
When it comes to 2 in 1 I think of lenovo yoga series