From general publick view, Surge Protectors are a "nice to have" item. Each Surge protection device has its own pros/cons and purchase price. Some are portable and some are fixed. For best protection (as proactive insurance), I'd install a 2 x Tier system.
Tier 1 - This involves installing an RV Surge protector on your RVs main line. Something that has an LED "number" Display - to show current AC levels and can visually show the different variances - as other RVs plug into the same pony panel. My Jayco has a simple Surge Protection with simple LED on/off light system that works great but to view its AC levels (re: 109 Volts or pershaps 125 Volts), I need to use my hand held volt meter. Add the cost of Surge Protector and hand held Volt Meter and I could have bought a more expensive RV Surge Protector with LED "number" display system - instead of LED off/on light display.
For Tier 2 Surge Protection, simply buy lots of Socket Surge Protectors and install inside your TT. For example, http://www.ottawaprices.ca/WebProduc...VFL200-CAN.jpg
on your Coffee pot, another one on our Fridge, another one on your TV/DVD system.
Tier 1 protection allows "main line" insurance. Tier 2 proteciton allows "individual" outlet protection insurance. If wondering, my Jayco has both and they work great. My future RV/TT will use 2 Tier protection as well. IMO, RV Surge protection is worth the cost - due to high cost of electronic replacements. Fridge circuit board, AC circuit board and Furnance circuit board replacements are very expensive. To me, RV Surge protection on "main line" should be minimum code.