Speaker upgrade question.

Hi all, 
I haven't been here for quite a while as I've been happy with my KEF Reference Three-Twos driven by a Musical Fidelity A308. They're both vintage but they sound great together and fit my somewhat weird room. I'm pondering spending some bucks in the 3-6K range for new (used) speakers and I have a few questions. Thanks ahead of time for anyone who's not too busy to help.
First, would I be  upgrading beyond what my amp is capable of keeping up with? The MF is fairly powerful, but I'm not sure of its limitations since they don't show up in my current system.
Secondly, how high up the price ladder would I need to go before I'd find speakers that offer an obvious improvement over my KEFs to most ears. There would be little point to pony up money for a comparable sound, however much I subjectively prefer subtle differences.
Finally, for reference purposes, can anyone tell me how the following modern speakers might compare or contrast with mine? (Some aren't in my price range, I know) Triton 1R, Kef R7, comparably priced Monitor, Revel, Gato, Paradigm, etc. I wouldn't mind a bit more punch and a bit more bass than I have now, mostly just to experience a different sound - I respect the KEF signature sound.
I know that sometimes it's hard to accept the premises of these types of questions since such matters are so subjective and a lot of folks like to lobby for their favorite brands. I guess I'm not seeking advice about what to buy. I just want to understand the benefit to me of more modern speakers. It's quite possible it makes no sense for me to upgrade.
Thanks again.
Lots of room gain that close to the wall - stick with KEF a real engineering and sound company but change the DAC first

The best way would be to bring a few pairs (not necessarly at once) of newer speakers home and check what it is all about. Maybe a member in your area has a pair of whatever brand and model and you could compare.
Marc, if you like the KEF signature sound of your Reference Model 3.2s, you will be hard pressed to find a speaker that you prefer. I have the Model ones and Model Twos and IMHO they are some of the best speakers that I have heard. I prefer their sound to the newer KEF speakers that I have heard. I also prefer them to any Triton, Paradigm or Tetkton speakers that I have heard. If it were me, I would just keep the 3.2s. 
By the way, I never felt a need for a sub with my KEF Reference speakers and your 3.2s should reach deeper than my Ones or Twos.
A few years ago my neighbour had the same question about his KEF103's. I suggested that he spend some money improving the crossover components; that is, changing cheap capacitors for fine audiophile capacitors, etc. The sort of thing that no manufacturer can do.

Anyway, he went for it, I rebuilt the crossovers with premium components, and he couldn't be happier. The sound is similar to what he had, but far, far better: more refined, accurate, punchy, and easy on the ears. So if you like what you have, but ... Then I suggest that you upgrade the crossover. Don't change anything but the quality of the parts, so a 2uF cap is still a 2uF cap - just that the one you are putting in is an MIT RTX costing about 100 times what the original part cost.

You might need a new box to hold the new components, as they tend to be a lot bigger as well as more expensive. Parts can be obtained from Parts Connexion or Michael Percy.

DIY forever!