>> I am planning a short 2 days trip ... targeting Lake Geneva and Montruex / Vevey towns... I am planning to base myself at Vevey or Montreux. Which one is more recommended?
Both are nice towns with beautiful waterfront promenades and lake and mountain views.
Montreux has the advantage of having its railway station close to the wharf, making transfers between train and boat quite easy. The station in Vevey is slightly uphill from the wharf, about 10 minutes walk.
Vevey has a picturesque "old town" area close to the waterfront: Rue du Lac. There is also a beautiful historic carousel on the waterfront. Montreux has Chillon Castle. Boat trips can be taken from both Montreux and Vevey.
>> We will be travelling with an infant (around 5 months) and 2 other kids (9 &5) Are both towns reasonably comfortable for pram manoeuvres?
The lakeside promenades are ideal for prams.
>> Also would you recommend trip to Rochers de Naye with baby?
Rochers-de-Naye is at an altitude of over 2,000 metres. I would consult your doctor before taking an infant to that altitude.
>> Promenade walk (is it along Lake Geneva ?)
>> any other gem to visit ?
A short train trip through the vineyards is beautiful. I described how to do it in my post of May 19, 2017 - 4:32 AM on the following page, and included some photos:
>> Any waterfalls or cable cars /cogwheels journeys in this region?
Yes, but I haven't been on these myself, so hopefully someone else can give you further advice:
Les Avants-Sonloup funicular, altitude 1,156 metres (from Montreux)
Funicular Territet (Montreux) to Glion, altitude 687 metres
Les Pléiades, altitude 1,361 metres (from Vevey)
Funicular railway Vevey-Mont-Pèlerin, altitude 1,080 metres