Your opinions needed on wysiwyg software for IM purposes

Hi.

I'm currently working on a fairly big project in the mortgage niche in the uk. We have a web guy working for us, he's a good guy but very slow to get things done. This is getting frustrating for us as a lot of changes are going to be needed to be made in the long term. We have a lot of pressure on us to get things finished asap and it won't get done the way we want it to get done with the guy we're using at the moment.

We want to do the work ourselves however the only software I feel comfortable using to a decent level in serif webplus x5. It's quite an obscure peice of software but very good for beginners. You can build very professional looking websites really easily. It's almost like doing desktop publishing but for website. Lots of stuff you can just drag and drop and move about.

I've heard elsewhere though that using this kind of software makes the code a lot more convoluted and messy than it needs to be and that this can have a negative effects on a sites loading speed. Also I've heard that this can negative effect a sites rankings in google.

I used to work at the company and they have a great reputation. However, because they cannot compete with the likes of dreamweaver, they tend to market themselves at the smaller businesses. Just confused if there is any reason why i shouldn't use it for a big website in a high competition environment. we will be competing for some very highly searched terms.

Anybody have any thoughts or experiences with this that they can share with me?? It would take a lot of time to take the site as it is (currently using cms software called umbraco) and convert it into serif.

In my experience I've heard a lot of people say certain thing negatively influence a sites ranking and it ends up being completely untrue when I've tested it myself. that's why i thought i would ask here.

What is everybodies opinions on this?

Thanks a lot in advance for any advice you can give me.

David