I'm keen to understand the nature of the pre UCE bikes, especially with regard to built quality, comfort, etc. It seems from what you're saying though, they are a little fragile and need a lot of looking after.
The limiting factor in the old design is the metallurgy and as a result the tolerances and finishes and the choices they made in the lubrication. It's stuff they couldn't change on an Indian design budget of the 1980's. There are bits of sand cast iron and bronze and brass in there with cast surfaces and not enough oil. Hence, you get 500cc's making 18 hp tops and only able to maintain that for short periods. The standard Bullet's cruising speed is something in the order of 55 mph while top speed is something over 70, a much bigger differential than a modern bike. By the same reasoning as roughly made bits move about you'll have constant adjustments to make. It's nothing like as much as the owners club people like to talk about though, they are into adjusting pushrods as much as riding so you don't IMHO get the full picture.
Quality wise I found very little wrong with them, certainly better than a Ural. Comfort wise I think it's about as good as it gets.
If the EFI is a blank paper design as it seems to be, there is no reason it won't be able to put out 25 hp all day for a long time and hence cruise at 70. It'll have machining tolerances and materials that would have looked like science fiction in 1948. The worry to me is that they've cut corners and used bits of the previous motor. The fact it's unit construction to me suggests it is a totally new design though. The 5-speed gearbox they introduced was a bit of a practical engineering masterpiece, I just hope they applied the same ideas to the new motor.
I'd let someone else put a few thousand miles on one first and see how it fares though.
Andy