I had a thread in chat about this (I decided on the polti and am very happy with it). As the chat threads expire after 30 days I came over here to put the reviews I did of it into a thread here so that people in the future who are searching like I did for info, can find it. Since you're asking the same question, I hope you don't mind if I cut and paste what I wrote here into your thread. Hope it's useful info for you in making your decision.
I bought the Polti Evolution from Lakeland and said the following...
Ooh it's very exciting and I like it very much. It's not the total miracle machine I was (unrealistically) hoping for, but it's bloody good. I realised, too, just how much the chemical smell puts me off cleaning usually - I'm really sensitive to smells and especially in confined spaces like the bathroom I find it really unpleasant spraying cleaners around and inhaling them while I'm scrubbing.
With the Polti, no smell, although there's a faint plasticky odour to start with, which I assume is from the plastic parts heating up. I also really love the fact that it's sterilising things - I'm no clean freak (I'm so shamefully far from being a clean freak that I've no right to even use the words in a sentence), but it's great to steam the chopping boards etc after washing and know that they're properly clean.
Ok here's the stuff I had a brief go at yesterday and what the results were:
Kitchen floor - did a test couple of tiles.
Our kitchen floor is properly manky. It's tiled with cheap adhesive tiles that were already grey and sad when we moved in nearly four years ago. However much DP mops it, it never looks clean. And he doesn't mop it all that often! I was hoping for a miracle here, that it would bring them up sparklingly black and white. It didn't. It cleaned them and they looked a bit better, but I think they're well beyond ever looking sparkly again tbh. sad DP will use the Polti to do the whole floor later, so further feedback to come.
Sink and draining board.
Stainless steel that's all scratched and marked. Again, not a miracle cure, but it did well. Using the 120degree concentrator tool and a scrubbing brush, the brown marks came off really well with a bit of elbow grease. The limescale was shifting but it took a lot of scubbing. It would probably come off as well with chemicals and scrubbing.
The stuff that came out of the sink overflow when I directed the jet of steam down there was indescribable. Actually I could describe it, but you really wouldn't want me to.
Cooker
The hob came up beautifully. It's a steel hob with 5 gas rings and I'd let it get manky in anticipation of the steamer's arrival. Usually I'd have sprayed a load of flash onto it, waited while it soaked in and then scrubbed it. With the Polti I just steamed it, then wiped with a sponge and majority of bits came off cleanly. Another couple of blasts for the tough stuff and it was sparkling. The steam seems to almost emulsify the fat so that you can wipe it without any smearing, and it rinses really easily from the sponge too. I even had a go at the gas hob bits themselves, and was astonished to descover bits of silver peeping through the black at me. blush
I then had a quick go at the small oven, which is truly revolting. It blew out loads of congealed fat [boak] from behind the glass on the door, and started to lift the congealed dirt. It does take elbow grease though - the steam lift the dirt but you still have to scrub it.
Venetian blind in kitchen.
Never been cleaned I don't think. blush Dusty, greasy, grimy. It took ages, but I blasted off the dust etc from each slat. Probably would have been as effective to do it with wipes, but the steam is more fun. grin
Walls and cobwebs. Just blasting with steam doesn't get rid of the cobwebs and dirt - you do have to wipe. However you can use the small brush with towelling cover on the extension tubes. I didn't, because it only came with one measly cover and I'm saving that to use of upholstery and didn't want to get it manky.
Carpet
Now this was bloody miraculous! I tested it on a patch of carpet near the patio doors where the dog comes in with muddy feet. It's a revolting carpet anyway (was when we moved in), which we can't afford to replace. The dirt almost leaps out of the carpet onto the cloth (i used the direct steam jet and a handheld cloth to dab it). I think it might also work well if you steam it then hoover, as it seems to magically lift the dirt up. Better result than a rug doctor on that little patch, and left the carpet much drier. I'll be doing lots more testing!
Walls
Got stubborn marks off the paintwork really easily (that I was unable to get off before), although you have to be careful not to melt the paint.
Sofa
Haven't tried the sofa properly yet, but it was amazing at lifting a wax stain that's been there for over a decade. The patch is still stiff, but looks much better.
Also, the steam is properly dry steam - you don't feel like you're in a sauna when you're using it and it doesn't feel hot on your face. It's bloody hot at the point of exit though. It does produce a fair bit of moisture on hard surfaces though, which you have to wipe up.
Ok that's enough for now, I'm happy to update more when I've done more steaming, if anyone's interested. At the moment I'm a woman obsessed - I look around the house and just see a succession of steamable things!