That's a good question ...
Cost wise ...
You have to weigh the cost of those 6045's against the future costs of whatever you want to upgrade to
Ya, it's a lot to pay now for the top end stuff, so, if you'd like to upgrade those 6045's later, look at what the resale value of those pumps is, and do some math ...
I'm not trying to push the Vortechs on you, and I'm sure Steve isn't either, but they do hold their value
Adjustability wise ...
I couldn't be happier with my pair of MP10wES
Best money I ever spent on prop pumps
I had a bit of a learning curve after I got them, but they are awesome, and I, after years of internal ugly powerheads, love the low profile
I'm still waiting to see if any Tunze users are going to chime in as they have their benifits too, such as better placement / angles of flow / low noise ...