Merkur Futur here. I've been using Derby blades lately.
I've seen the Futur criticized for being too heavy. It's the only DE I've every used, so, as far as I'm concerned, this is how heavy a DE razor is. I guess that I just don't know any better.
I've seen the Futur criticized for being too long. But, it's shorter than the Sensor I used for twenty-some years. And, again, this is the only DE razor I've ever used so, as far as I know, this is how long DE razors are. I guess that I just don't know any better.
I've seen the Futur criticized as too big. But I find that it is so well-designed that I have no problems in the tightest of places. It's better under my nose than my Sensor ever was. And, again, it's the only DE razor I've ever used; so, as far as I know, this is how big DE razors are. I guess that I just don't know any better.
I've heard the Futur criticized as slippery. I have the polished chrome model. I have had no problems... as long as my hands aren't soapy. Just water-wet hands are no problem at all.
It's easy to change the blade and easy to clean and obviously built to last a lifetime. So, I like it.