0.75 & 0.80 5th Gear Ratios

I had posted this under 'Running Gear' but not much feedback there, so:

What experience have people had using either of these taller ratios in a GTI gearbox? I'm shortly going for a KR conversion & keeping my FD gearbox. I've seen that the 5th gear swap is possible but would like to know how it affects the car overall. Does 5th become purely a motorway gear? Does dropping into 4th become awkward? I can imagine the positive aspects are very enjoyable!

i have changed the 5th in my acd box which has the very simial gearing. i put a 0.75 gear out of a 4t box i had, it is great on the motorway it drops the rpm over 1000 at 80 but have found the gap between 4th n 5th a little large for fast driving on country road ect have to take it close to the limit in 4th to carry enough rpm through to 5th.
hope thats some help

Thanks for your input mate. Been having a dabble on the gear ratio guide. I think the .80 would be the more suitable option for me.