Upgrading 5.1 set bit by bit - does it work ok?

[PardonTheWait]

This might seem a bit of a strange question, but oh well, I don't know so I'll ask!

I recently got a new TV, and a new amp (Yamaha RX-V367). I'm using the amp with my current Tannoy FX5.1 system which I've had for years, the earlier one with the centre speaker that's the same as the rest.

I'm pretty happy with the speakers as a whole but if one thing wants upgrading it's the centre, for two reasons:

a) it looks stupid

b) it just feels like it could be better, the centre channel could be clearer.

Does upgrading a 5.1 system piecemeal like this cause problems? If I get a new centre will it sound ... 'wrong'?

If it's a sensible option, do you have any recommendations for something that would work? I like the look of the Mordaunt Short alumni 5 but I think that's just because it's not stupid money and it looks pretty, does anyone have one? (or the set)

Oh there's also the SFX5.1 centre which is included with the newer version of my speaker set, I assume that would be a safe bet being from a very similar set of speakers? £70.

Thanks

 

[PardonTheWait]

So, looks like I'll either get the SFX centre for £70 and leave the rest, as it should blend in perfectly, or save up a bit and do the front three. I don't have that sort of cash at the moment (to do all three), so I shall have a little bit of a ponder on it. Can't afford anything til next month anyway so loads of time to think about it.