I picked up an SLx one, only 3 port, but it was a tad expensive (considering it feels like a cheap lump of plastic). Main reason I got that one was because it of it's IR receiver. Picture quality is top though (even given its nasty casing).
Just got the Joytech switcher through today from Amazon and can confirm there is no picture loss whatsoever and fantastic value at £29.99 you can't go wrong.
Aye I've got the joytech switcher it's great,got it stuck to the back of my TV and use the remote to switch it via I.R.
£30 is a steal for this,buy with confidence.