...if it is just for checking then you will be fine to export from indesign to pdf. The client will see what you see, just be aware that indesign can create different versions of pdf files, some of which will only open in Acrobat Reader 5 or later...
...in your export preset options there is a compatibilty pull down menu from 1.3 to 1.6 pdfs, i nearly always use 1.3 as this will open in any version of Acrobat Reader right back to Acrobat Reader 4...
...if your lost in the preset pdf window then just use 'high quality' preset, if it is a massive resulting pdf file then create a even more compressed version by choosing 'smallest file size'. Note that this options will create compression artifacts in bitmap images.
If the client complains that vector lines all look rough and jagged, advise them to turn on text smoothing, lineart smoothing and image smoothing in their acrobat preferences.
Some artworked files that require transparency flattening on export to high resolution pdf can sometimes have very faint lines running through the effects when viewed in Acrobat. This is caused by acrobat having smoothing enabled, a screen rendering issue that won't effecting final output.
have fun!
andrew