I write PDFs from LO files regularly and I have never found a difference in the appearance of the LO original and the pdf. I produced one 40-page manual with tables and graphics this way.LO to pdf conversions look to be okay - I'm still checking this.
I did have one early problem - a table in LO on screen showed feint borders but these didn't show in the pdf. I realised they didn't show in a print from the LO file either - it was because I hadn't set any. The lines displayed on screen were guidance lines only.